diff --git a/.gitignore b/.gitignore
index d0c282a..6e3d082 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,4 +15,5 @@ tmpclaude-*
 *.png
 data/
 Excel/
+Access/
 VBA/
\ No newline at end of file
diff --git a/CLAUDE.md b/CLAUDE.md
index 74da38c..8caa526 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -4,7 +4,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Project Overview
 
-**Auto_BOM** is a VBA code extraction and management toolkit for Excel-based Bill of Materials (BOM) processing. The project provides Python tools to extract VBA code from `.xlsm` files, manage it externally, and import it back into Excel.
+**Auto_BOM** is a VBA code extraction and management toolkit for Excel-based Bill of Materials (BOM) processing. The project provides Python tools to extract VBA code from `.xlsm` (Excel) and `.accdb` (Access) files, manage it externally, and import it back.
 
 The VBA code implements a hierarchical BOM management system with:
 - **clsBOMManager**: Main class managing BOM data structure and category relationships
@@ -16,14 +16,15 @@ The VBA code implements a hierarchical BOM management system with:
 ```
 Auto_BOM/
 ├── Excel/              # Source Excel files (.xlsm) - gitignored
+├── Access/             # Source Access files (.accdb) - gitignored
 ├── VBA/                # Extracted VBA code - gitignored
 │   ├── Modules/        # Standard modules (.bas)
 │   ├── ClassModules/   # Class modules (.cls)
 │   ├── DocumentModules/# Sheet/workbook modules (.cls)
 │   ├── Forms/          # User forms
 │   └── vba_metadata.json # Module metadata for import
-├── extract_vba.py      # Extract VBA from Excel files
-├── import_vba.py      # Import VBA back to Excel files
+├── extract_vba.py      # Extract VBA from Excel/Access files
+├── import_vba.py      # Import VBA back to Excel/Access files
 ├── main.py            # Empty placeholder
 └── requirements.txt   # Python dependencies
 ```
@@ -40,8 +41,8 @@ pip install -r requirements.txt
 ```
 
 **Dependencies:**
-- `pywin32>=306` - Windows COM interface for Excel automation (Windows only)
-- `oletools>=0.60` - Alternative VBA extraction without Excel dependency
+- `pywin32>=306` - Windows COM interface for Excel/Access automation (Windows only)
+- `oletools>=0.60` - Alternative VBA extraction without Excel dependency (Excel only)
 
 ## Common Commands
 
@@ -51,20 +52,24 @@ pip install -r requirements.txt
 python extract_vba.py
 ```
 
-Two extraction methods available:
+**Excel (.xlsm)** - Two extraction methods available:
 1. **COM Interface** (recommended) - Requires Microsoft Excel, more reliable
 2. **olevba Library** - No Excel required, uses oletools
 
-For COM method, ensure Excel trusts VBA access:
+**Access (.accdb)** - Only COM Interface supported (requires Microsoft Access)
+
+For COM method, ensure the application trusts VBA access:
 - Excel > Options > Trust Center > Trust Center Settings
 - Check "Trust access to the VBA project object model"
 
 ### Import VBA Code
 ```bash
-# Import from VBA/ directory back to Excel
-python import_vba.py VBA/vba_metadata.json
+# Import from VBA/ directory back to Excel or Access
+python import_vba.py
 ```
 
+Set `TARGET_FILE` in `.env` to the target `.xlsm` or `.accdb` file path.
+
 ## VBA Code Architecture
 
 ### BOM Data Model
@@ -98,12 +103,12 @@ The VBA system implements a hierarchical category-based material management:
 
 - Cleans `Attribute` statements from exported code for readability
 - Automatically categorizes modules by type (Standard/Class/Document/Form)
-- Generates `vba_metadata.json` tracking source file, module names, types, and file mappings
 - Module type detection based on naming conventions (mod_=Standard, cls=Class, sheet=Document)
+- Auto-detects file type by extension (.xlsm → Excel, .accdb → Access)
 
 ### VBA Import (import_vba.py)
 
-- Uses Windows COM to interact with Excel
+- Uses Windows COM to interact with Excel or Access
 - **Critical fix for ClassModules**: Reconstructs `VERSION 1.0 CLASS` header before import
 - **Encoding handling**: Uses GB18030 for temp files to prevent Chinese character corruption
 - Path recognition logic handles relative/absolute paths in metadata
@@ -125,15 +130,16 @@ The `.vscode/settings.json` associates `.cls` files with Visual Basic syntax hig
 ## Platform Requirements
 
 - **Windows required** for import functionality (COM interface)
-- **Microsoft Excel** required for COM-based extraction/import
-- Cross-platform extraction possible with oletools (no Excel needed)
+- **Microsoft Excel** required for Excel COM-based extraction/import
+- **Microsoft Access** required for Access COM-based extraction/import
+- Cross-platform extraction possible with oletools (Excel only, no Office needed)
 
 ## Git Workflow
 
 The `.gitignore` excludes:
 - Virtual environment (`.venv/`)
 - Build artifacts (`build/`, `dist/`)
-- Project data (`Excel/`, `VBA/`)
+- Project data (`Excel/`, `Access/`, `VBA/`)
 - Claude temporary files (`.claude/`, `tmpclaude-*`)
 
 Only commit code changes, not extracted VBA or Excel files.