diff --git a/B01_Dashboard/B01_Dashboard_Api_Fetch.ts b/B01_Dashboard/B01_Dashboard_Api_Fetch.ts
index 2d4e01a6..e258ca87 100644
--- a/B01_Dashboard/B01_Dashboard_Api_Fetch.ts
+++ b/B01_Dashboard/B01_Dashboard_Api_Fetch.ts
@@ -117,6 +117,9 @@ export interface AuditLog {
   action: string;
   resource_type?: string | null;
   resource_id?: number | null;
+  /** 대상 식별자 문자열 — 프로젝트는 UUID 라 숫자 칸에 못 담는다 (2026-09-06). */
+  resource_ref?: string | null;
+  ip_address?: string | null;
   timestamp: string;
 }
 
diff --git a/B01_Dashboard/B01_Dashboard_Repository.py b/B01_Dashboard/B01_Dashboard_Repository.py
index fc772cbf..9bed97a0 100644
--- a/B01_Dashboard/B01_Dashboard_Repository.py
+++ b/B01_Dashboard/B01_Dashboard_Repository.py
@@ -10,6 +10,7 @@ from typing import Any
 import aiomysql
 import psutil
 
+from common_util.common_util_audit import record_audit
 from config.config_db import get_db_pool
 from config.config_system import ADMIN_EMAIL, EMAIL_REVERIFY_DAYS
 
@@ -256,7 +257,9 @@ async def get_project(project_id: str) -> dict[str, Any] | None:
         return await cursor.fetchone()
 
 
-async def update_project(project_id: str, data: dict[str, Any], actor_id: int) -> bool:
+async def update_project(
+    project_id: str, data: dict[str, Any], actor_id: int, request: Any | None = None
+) -> bool:
     pool = get_db_pool()
     async with pool.acquire() as connection, connection.cursor() as cursor:
         await connection.begin()
@@ -300,16 +303,19 @@ async def update_project(project_id: str, data: dict[str, Any], actor_id: int) -
             )
             changed = await cursor.fetchone() is not None
         else:
-            await cursor.execute(
-                """INSERT INTO system_audit_logs (user_id, action, resource_type, resource_id)
-                   VALUES (%s, 'PROJECT_UPDATE', 'project', NULL)""",
-                (actor_id,),
+            await record_audit(
+                cursor,
+                actor_id=actor_id,
+                action="PROJECT_UPDATE",
+                resource_type="project",
+                resource_ref=project_id,
+                request=request,
             )
         await connection.commit()
         return changed
 
 
-async def soft_delete_project(project_id: str, actor_id: int) -> bool:
+async def soft_delete_project(project_id: str, actor_id: int, request: Any | None = None) -> bool:
     pool = get_db_pool()
     async with pool.acquire() as connection, connection.cursor() as cursor:
         await connection.begin()
@@ -320,10 +326,13 @@ async def soft_delete_project(project_id: str, actor_id: int) -> bool:
         )
         changed = cursor.rowcount > 0
         if changed:
-            await cursor.execute(
-                """INSERT INTO system_audit_logs (user_id, action, resource_type, resource_id)
-                   VALUES (%s, 'PROJECT_DELETE', 'project', NULL)""",
-                (actor_id,),
+            await record_audit(
+                cursor,
+                actor_id=actor_id,
+                action="PROJECT_DELETE",
+                resource_type="project",
+                resource_ref=project_id,
+                request=request,
             )
         await connection.commit()
         return changed
@@ -447,7 +456,7 @@ async def list_audit_logs(limit: int, offset: int) -> dict[str, Any]:
         total = (await cursor.fetchone())["total"]
         await cursor.execute(
             """SELECT l.id, l.user_id, u.email, l.action, l.resource_type,
-                      l.resource_id, l.timestamp
+                      l.resource_id, l.resource_ref, l.ip_address, l.timestamp
                FROM system_audit_logs l LEFT JOIN users u ON u.id = l.user_id
                ORDER BY l.timestamp DESC LIMIT %s OFFSET %s""",
             (limit, offset),
diff --git a/B01_Dashboard/B01_Dashboard_Repository_Company.py b/B01_Dashboard/B01_Dashboard_Repository_Company.py
index e7a4eb12..c4a6ae6a 100644
--- a/B01_Dashboard/B01_Dashboard_Repository_Company.py
+++ b/B01_Dashboard/B01_Dashboard_Repository_Company.py
@@ -10,6 +10,7 @@ from typing import Any
 
 import aiomysql
 
+from common_util.common_util_audit import record_audit
 from config.config_db import get_db_pool
 
 from .B01_Dashboard_Repository import role_for_company
@@ -77,7 +78,9 @@ async def search_companies(query: str) -> list[dict[str, Any]]:
         return list(await cursor.fetchall())
 
 
-async def create_company(user_id: int, data: dict[str, Any]) -> dict[str, Any]:
+async def create_company(
+    user_id: int, data: dict[str, Any], request: Any | None = None
+) -> dict[str, Any]:
     pool = get_db_pool()
     async with pool.acquire() as connection, connection.cursor() as cursor:
         try:
@@ -104,10 +107,13 @@ async def create_company(user_id: int, data: dict[str, Any]) -> dict[str, Any]:
                    WHERE id = %s""",
                 (company_id, user_id),
             )
-            await cursor.execute(
-                """INSERT INTO system_audit_logs (user_id, action, resource_type, resource_id)
-                   VALUES (%s, 'COMPANY_CREATE', 'company', %s)""",
-                (user_id, company_id),
+            await record_audit(
+                cursor,
+                actor_id=user_id,
+                action="COMPANY_CREATE",
+                resource_type="company",
+                resource_ref=company_id,
+                request=request,
             )
             await connection.commit()
             return {"company_id": company_id, "status": "ACTIVE"}
@@ -116,7 +122,9 @@ async def create_company(user_id: int, data: dict[str, Any]) -> dict[str, Any]:
             raise
 
 
-async def create_system_company(actor_id: int, data: dict[str, Any]) -> dict[str, Any]:
+async def create_system_company(
+    actor_id: int, data: dict[str, Any], request: Any | None = None
+) -> dict[str, Any]:
     pool = get_db_pool()
     async with pool.acquire() as connection, connection.cursor() as cursor:
         try:
@@ -135,10 +143,13 @@ async def create_system_company(actor_id: int, data: dict[str, Any]) -> dict[str
                 ),
             )
             company_id = cursor.lastrowid
-            await cursor.execute(
-                """INSERT INTO system_audit_logs (user_id, action, resource_type, resource_id)
-                   VALUES (%s, 'COMPANY_CREATE', 'company', %s)""",
-                (actor_id, company_id),
+            await record_audit(
+                cursor,
+                actor_id=actor_id,
+                action="COMPANY_CREATE",
+                resource_type="company",
+                resource_ref=company_id,
+                request=request,
             )
             await connection.commit()
             return {"company_id": company_id, "status": "ACTIVE"}
diff --git a/B01_Dashboard/B01_Dashboard_Router.py b/B01_Dashboard/B01_Dashboard_Router.py
index 119651f8..1f4740cf 100644
--- a/B01_Dashboard/B01_Dashboard_Router.py
+++ b/B01_Dashboard/B01_Dashboard_Router.py
@@ -13,6 +13,7 @@ from fastapi import (
     HTTPException,
     Path,
     Query,
+    Request,
     Response,
     UploadFile,
 )
@@ -196,10 +197,11 @@ async def user_company_search(
 
 @router.post("/user/company/create")
 async def user_company_create(
+    request: Request,
     payload: CreateCompanyRequest,
     session: dict[str, Any] = Depends(verify_session),
 ):
-    result = await create_company(int(session["user_id"]), payload.model_dump())
+    result = await create_company(int(session["user_id"]), payload.model_dump(), request)
     return {"status": "success", **result}
 
 
@@ -369,6 +371,7 @@ async def admin_projects(session: dict[str, Any] = Depends(require_company_admin
 @router.put("/projects/{project_id}")
 async def dashboard_update_project(
     project_id: str,
+    request: Request,
     payload: UpdateProjectRequest,
     session: dict[str, Any] = Depends(verify_session),
 ):
@@ -387,7 +390,7 @@ async def dashboard_update_project(
         )
     await check_project_refs(int(project["company_id"]), data)
     member_ids = data.pop("member_user_ids", None)
-    if not await update_project(project_id, data, int(session["user_id"])):
+    if not await update_project(project_id, data, int(session["user_id"]), request):
         raise HTTPException(status_code=404, detail="프로젝트를 찾을 수 없습니다.")
     if member_ids is not None:
         # 만든 사람은 늘 참여자로 남는다.
@@ -398,6 +401,7 @@ async def dashboard_update_project(
 @router.delete("/projects/{project_id}")
 async def dashboard_delete_project(
     project_id: str,
+    request: Request,
     session: dict[str, Any] = Depends(verify_session),
 ):
     project = await get_project(project_id)
@@ -413,7 +417,7 @@ async def dashboard_delete_project(
 
     # 개발 PC에서만 하드 삭제. 배포 기본값은 지금까지처럼 소프트 삭제다.
     delete_project = hard_delete_project if PROJECT_DELETE_HARD_ENABLED else soft_delete_project
-    if not await delete_project(project_id, int(session["user_id"])):
+    if not await delete_project(project_id, int(session["user_id"]), request):
         raise HTTPException(status_code=404, detail="프로젝트를 찾을 수 없습니다.")
     return {"status": "success"}
 
@@ -426,10 +430,11 @@ async def system_companies(session: dict[str, Any] = Depends(require_system_admi
 
 @router.post("/admin/companies")
 async def system_create_company(
+    request: Request,
     payload: CreateCompanyRequest,
     session: dict[str, Any] = Depends(require_system_admin),
 ):
-    result = await create_company(int(session["user_id"]), payload.model_dump())
+    result = await create_company(int(session["user_id"]), payload.model_dump(), request)
     return {"status": "success", **result}
 
 
diff --git a/B01_Dashboard/B01_Dashboard_UI_Admin.ts b/B01_Dashboard/B01_Dashboard_UI_Admin.ts
index 5bd3cbd4..7aca5024 100644
--- a/B01_Dashboard/B01_Dashboard_UI_Admin.ts
+++ b/B01_Dashboard/B01_Dashboard_UI_Admin.ts
@@ -80,8 +80,11 @@ function auditTarget(log: AuditLog): string {
   // 저장값은 소문자(`project`)로 들어온다 — 대문자로 맞춰 찾는다.
   const key = (log.resource_type ?? "").toUpperCase();
   const kind = TARGET_LABELS[key] ?? log.resource_type ?? "";
-  if (!kind) return "-";
-  return log.resource_id ? `${kind} #${log.resource_id}` : kind;
+  const reference = log.resource_ref ?? (log.resource_id ? String(log.resource_id) : "");
+  if (!kind) return reference || "-";
+  // 프로젝트 UUID 는 길어 앞 8자만 — 어느 프로젝트인지 가리기에는 충분하다.
+  const shortened = reference.length > 12 ? `${reference.slice(0, 8)}…` : reference;
+  return shortened ? `${kind} ${shortened}` : kind;
 }
 
 const TARGET_LABELS: Record<string, string> = {
@@ -98,12 +101,15 @@ export function auditLogTable(logs: AuditLog[]): HTMLElement {
       // 관리 버튼 열과 같은 말(「관리」)을 돌려 쓰던 것을 갈랐다 (2026-09-06 사용자 지적).
       L("B01_Dashboard_Table_Event"),
       L("B01_Dashboard_Table_Target"),
+      L("B01_Dashboard_Table_Origin"),
       L("B01_Dashboard_Table_When"),
     ],
     logs.map((log) => [
       text(log.email),
       text(log.action),
       text(auditTarget(log)),
+      // 접속 주소 — 기록이 없는 옛 줄은 빈칸으로 남는다 (2026-09-06부터 기록).
+      text(log.ip_address ?? "-"),
       // 날짜와 시각을 두 줄로 — 아랫줄이 작은 글씨라 행 높이는 그대로다.
       stackedCell(formatDate(log.timestamp), formatTime(log.timestamp)),
     ]),
diff --git a/B02_ProjRegister/B02_ProjRegister_Repository.py b/B02_ProjRegister/B02_ProjRegister_Repository.py
index 9c3d68b0..4714daa9 100644
--- a/B02_ProjRegister/B02_ProjRegister_Repository.py
+++ b/B02_ProjRegister/B02_ProjRegister_Repository.py
@@ -9,6 +9,7 @@ from uuid import uuid4
 
 import aiomysql
 
+from common_util.common_util_audit import record_audit
 from common_util.common_util_json import atomic_write_json
 from common_util.common_util_storage import PROJECT_STORAGE_LAYOUT_V2
 from common_util.common_util_workflow import load_project_workflow
@@ -43,6 +44,7 @@ def _initialize_project_storage(project_root: Path, project_id: str) -> None:
 
 async def create_project(
     *,
+    request: Any | None = None,
     user_id: int,
     company_id: int,
     name: str,
@@ -110,10 +112,13 @@ async def create_project(
             # 워크플로우 단계별 상태 초기화 시드
             await initialize_project_stages(cursor, project_id)
 
-            await cursor.execute(
-                """INSERT INTO system_audit_logs (user_id, action, resource_type, resource_id)
-                   VALUES (%s, 'PROJECT_CREATE', 'project', NULL)""",
-                (user_id,),
+            await record_audit(
+                cursor,
+                actor_id=user_id,
+                action="PROJECT_CREATE",
+                resource_type="project",
+                resource_ref=project_id,
+                request=request,
             )
             _initialize_project_storage(project_root, project_id)
             await connection.commit()
diff --git a/B02_ProjRegister/B02_ProjRegister_Router.py b/B02_ProjRegister/B02_ProjRegister_Router.py
index f8127d0c..54934c5f 100644
--- a/B02_ProjRegister/B02_ProjRegister_Router.py
+++ b/B02_ProjRegister/B02_ProjRegister_Router.py
@@ -2,7 +2,7 @@
 
 from typing import Any
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends, HTTPException, Request
 
 from B01_Dashboard.B01_Dashboard_Repository_Members import check_project_refs
 from common_util.common_util_auth import require_company
@@ -15,6 +15,7 @@ router = APIRouter(prefix="/api/b02", tags=["B02_ProjRegister"])
 
 @router.post("/project", response_model=CreateProjectResponse)
 async def post_project(
+    request: Request,
     payload: CreateProjectRequest,
     session: dict[str, Any] = Depends(require_company),
 ) -> CreateProjectResponse:
@@ -50,6 +51,7 @@ async def post_project(
 
     try:
         result = await create_project(
+            request=request,
             user_id=int(session["user_id"]),
             company_id=int(company_id),
             name=payload.name.strip(),
diff --git a/common_util/common_util_audit.py b/common_util/common_util_audit.py
new file mode 100644
index 00000000..e0dfd3a5
--- /dev/null
+++ b/common_util/common_util_audit.py
@@ -0,0 +1,84 @@
+"""시스템 로그 기록·정리 한 곳 (2026-09-06 사용자 확정).
+
+같은 INSERT 문이 여섯 자리에 흩어져 있었고, 대상(무엇에 한 일인가)과 접속 정보(어디서
+했는가)는 칸만 있고 값이 비어 있었다. 기록은 이 함수 하나로 모은다.
+
+보관 기간은 `AUDIT_LOG_RETENTION_DAYS`(기본 365일) — 사고 추적에 1년이면 충분하다는
+사용자 판단(2026-09-06). 임시 보관함 정리 루프가 돌 때 함께 지운다.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import datetime, timedelta, timezone
+from typing import Any
+
+from config.config_db import get_db_pool
+from config.config_system import AUDIT_LOG_RETENTION_DAYS
+
+logger = logging.getLogger(__name__)
+
+# 브라우저 문자열은 길다 — 표 칸은 TEXT 지만 화면·로그가 감당할 만큼만 자른다.
+_USER_AGENT_MAX = 300
+
+
+def request_origin(request: Any | None) -> tuple[str | None, str | None]:
+    """요청에서 접속 주소와 브라우저 문자열을 꺼낸다. 없으면 (None, None).
+
+    프록시 뒤에서는 `X-Forwarded-For` 의 **첫 주소**가 실제 사용자다.
+    """
+    if request is None:
+        return None, None
+    try:
+        forwarded = request.headers.get("x-forwarded-for")
+        address = forwarded.split(",")[0].strip() if forwarded else None
+        if not address and request.client is not None:
+            address = request.client.host
+        agent = (request.headers.get("user-agent") or "")[:_USER_AGENT_MAX] or None
+        return address, agent
+    except Exception:  # 기록이 본 작업을 막으면 안 된다.
+        return None, None
+
+
+async def record_audit(
+    cursor: Any,
+    *,
+    actor_id: int,
+    action: str,
+    resource_type: str | None = None,
+    resource_ref: str | int | None = None,
+    request: Any | None = None,
+) -> None:
+    """시스템 로그 한 줄을 적는다 — 호출부의 트랜잭션(cursor)에 얹는다.
+
+    `resource_ref` 는 프로젝트 UUID 처럼 문자열이어도 되고 숫자여도 된다. 숫자면 옛
+    `resource_id` 칸에도 같이 넣어 예전 기록과 같은 모양을 지킨다.
+    """
+    reference = None if resource_ref is None else str(resource_ref)
+    numeric = int(resource_ref) if isinstance(resource_ref, int) else None
+    address, agent = request_origin(request)
+    await cursor.execute(
+        """INSERT INTO system_audit_logs
+               (user_id, action, resource_type, resource_id, resource_ref, ip_address, user_agent)
+           VALUES (%s, %s, %s, %s, %s, %s, %s)""",
+        (actor_id, action, resource_type, numeric, reference, address, agent),
+    )
+
+
+async def purge_expired_audit_logs() -> int:
+    """보관 기간이 지난 시스템 로그를 지운다. 지운 줄 수를 돌려준다."""
+    cutoff = datetime.now(timezone.utc) - timedelta(days=max(1, AUDIT_LOG_RETENTION_DAYS))
+    pool = get_db_pool()
+    try:
+        async with pool.acquire() as connection, connection.cursor() as cursor:
+            await cursor.execute("DELETE FROM system_audit_logs WHERE timestamp < %s", (cutoff,))
+            removed = cursor.rowcount
+            if removed:
+                await connection.commit()
+                logger.info(
+                    "시스템 로그 정리: %d건 삭제 (보관 %d일)", removed, AUDIT_LOG_RETENTION_DAYS
+                )
+            return removed
+    except Exception:
+        logger.exception("시스템 로그 정리 실패")
+        return 0
diff --git a/common_util/common_util_project_delete.py b/common_util/common_util_project_delete.py
index 3008e4a2..7aa318bb 100644
--- a/common_util/common_util_project_delete.py
+++ b/common_util/common_util_project_delete.py
@@ -8,14 +8,16 @@
 
 import logging
 import shutil
+from typing import Any
 
+from common_util.common_util_audit import record_audit
 from common_util.common_util_storage import resolve_project_root_for_delete
 from config.config_db import get_db_pool
 
 logger = logging.getLogger(__name__)
 
 
-async def hard_delete_project(project_id: str, actor_id: int) -> bool:
+async def hard_delete_project(project_id: str, actor_id: int, request: Any | None = None) -> bool:
     """프로젝트를 DB와 영구저장소에서 완전히 지운다. 되돌릴 수 없다.
 
     자식 테이블은 나열하지 않는다 — `projects.id`를 참조하는 테이블이 전부
@@ -60,10 +62,13 @@ async def hard_delete_project(project_id: str, actor_id: int) -> bool:
             await connection.rollback()
             return False
         # 감사 기록은 프로젝트가 사라진 뒤에도 남는다. resource_id는 FK가 없어 고아가 되지 않는다.
-        await cursor.execute(
-            """INSERT INTO system_audit_logs (user_id, action, resource_type, resource_id)
-               VALUES (%s, 'PROJECT_HARD_DELETE', 'project', NULL)""",
-            (actor_id,),
+        await record_audit(
+            cursor,
+            actor_id=actor_id,
+            action="PROJECT_HARD_DELETE",
+            resource_type="project",
+            resource_ref=project_id,
+            request=request,
         )
         await connection.commit()
 
diff --git a/common_util/common_util_temp_cleanup.py b/common_util/common_util_temp_cleanup.py
index cc81af03..d864c547 100644
--- a/common_util/common_util_temp_cleanup.py
+++ b/common_util/common_util_temp_cleanup.py
@@ -14,6 +14,7 @@ from B03_FileInput.B03_FileInput_Repository_Temp import (
     delete_temp_batch,
     list_expired_temp_batches,
 )
+from common_util.common_util_audit import purge_expired_audit_logs
 from common_util.common_util_storage import resolve_temp_batch_path, temp_upload_root
 from config.config_db import get_db_pool
 from config.config_system import (
@@ -81,4 +82,6 @@ async def cleanup_expired_temp_uploads_loop() -> None:
         removed = await cleanup_expired_temp_uploads()
         if removed:
             logger.info("임시 보관함 정리 완료: %d건 삭제", removed)
+        # 시스템 로그 보관 기간 정리도 같은 주기에 얹는다 — 루프를 따로 두지 않는다.
+        await purge_expired_audit_logs()
         await asyncio.sleep(interval_seconds)
diff --git a/config/config_system.py b/config/config_system.py
index 701e782e..1d29b57c 100644
--- a/config/config_system.py
+++ b/config/config_system.py
@@ -98,6 +98,8 @@ CHUNK_RETENTION_HOURS = int(os.getenv("CHUNK_RETENTION_HOURS", "24"))
 # 운영하며 조정할 값이라 여기서 관리한다(2026-08-08 사용자 지시).
 TEMP_UPLOAD_DIR_NAME = os.getenv("TEMP_UPLOAD_DIR_NAME", "tmp")
 TEMP_UPLOAD_RETENTION_DAYS = int(os.getenv("TEMP_UPLOAD_RETENTION_DAYS", "30"))
+# 시스템 로그(누가 무엇을 했나) 보관 기간 — 사고 추적에 1년 (2026-09-06 사용자 확정).
+AUDIT_LOG_RETENTION_DAYS = int(os.getenv("AUDIT_LOG_RETENTION_DAYS", "365"))
 TEMP_UPLOAD_CLEANUP_INTERVAL_HOURS = int(os.getenv("TEMP_UPLOAD_CLEANUP_INTERVAL_HOURS", "6"))
 MERGE_TIMEOUT_SECONDS = int(os.getenv("MERGE_TIMEOUT_SECONDS", "3600"))
 SEND_ANALYSIS_COMPLETION_EMAIL = (
diff --git a/db_management/017_audit_log_detail.sql b/db_management/017_audit_log_detail.sql
new file mode 100644
index 00000000..8afbbed2
--- /dev/null
+++ b/db_management/017_audit_log_detail.sql
@@ -0,0 +1,13 @@
+-- 017_audit_log_detail.sql
+-- 시스템 로그에 「무엇에」 한 일인지와 「어디서」 했는지를 남긴다 (2026-09-06 사용자 확정).
+--
+-- 기존 `resource_id` 는 INT 라 프로젝트 id(UUID 문자열)를 담지 못해 늘 NULL 로 들어갔다.
+-- 문자 칸을 따로 두어 프로젝트·회사·사용자 어느 쪽이든 그대로 적는다.
+-- IP·브라우저 칸(`ip_address`·`user_agent`)은 004 에서 이미 만들어 두었으나 값을 넣는
+-- 코드가 없었다 — 이 마이그레이션 뒤부터 기록한다.
+
+ALTER TABLE system_audit_logs
+  ADD COLUMN IF NOT EXISTS resource_ref VARCHAR(64) NULL
+    COMMENT '대상 식별자 (프로젝트 UUID 등 문자열). 숫자 대상은 resource_id 와 같이 채운다';
+
+-- 보관 기간(기본 365일) 정리가 날짜로 훑으므로 인덱스는 004 의 timestamp 인덱스를 그대로 쓴다.
diff --git a/ui_template/ui_template_locale_b1.ts b/ui_template/ui_template_locale_b1.ts
index e12e1569..69fe4d01 100644
--- a/ui_template/ui_template_locale_b1.ts
+++ b/ui_template/ui_template_locale_b1.ts
@@ -138,6 +138,7 @@ export const ui_locales_b1 = {
   B01_Dashboard_Table_Action: ["관리", "Action"],
   B01_Dashboard_Table_Event: ["동작", "Event"],
   B01_Dashboard_Table_Target: ["대상", "Target"],
+  B01_Dashboard_Table_Origin: ["접속 주소", "From"],
   B01_Dashboard_Table_When: ["일시", "When"],
   B01_Dashboard_Table_Owner: ["소유자", "Owner"],
   B01_Dashboard_Field_BusinessNumber: ["사업자등록번호", "Business number"],