diff --git a/.commit-check.yml b/.commit-check.yml
index 7d5e579..35052d6 100644
--- a/.commit-check.yml
+++ b/.commit-check.yml
@@ -23,3 +23,8 @@ checks:
     regex: ^.+@.+$
     error: The committer email seems invalid
     suggest: run command `git config user.email yourname@example.com`
+
+  - check: merge_base
+    regex: main # it can be master, develop, devel etc based on your project.
+    error: Current branch is not rebased onto target branch
+    suggest: please ensure your branch is rebased with the target branch
diff --git a/.github/workflows/commit-check.yml b/.github/workflows/commit-check.yml
index 7ee0be4..dc398fd 100644
--- a/.github/workflows/commit-check.yml
+++ b/.github/workflows/commit-check.yml
@@ -15,6 +15,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.head.sha }}  # checkout PR HEAD commit
+          fetch-depth: 0  # fetch all history for all branches and tags
       - uses: ./ # self test
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # use GITHUB_TOKEN because of use pr-comments
@@ -24,5 +25,6 @@ jobs:
           author-name: true
           author-email: true
           commit-signoff: true
+          merge-base: true
           job-summary: true
           pr-comments: ${{ github.event_name == 'pull_request' }}
diff --git a/README.md b/README.md
index e58e79c..a25d56f 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.head.sha }}  # checkout PR HEAD commit
+          fetch-depth: 0  # required for merge-base check
       - uses: commit-check/commit-check-action@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # use GITHUB_TOKEN because of use pr-comments
@@ -39,6 +40,7 @@ jobs:
           author-name: true
           author-email: true
           commit-signoff: true
+          merge-base: false
           job-summary: true
           pr-comments: ${{ github.event_name == 'pull_request' }}
 ```
@@ -59,19 +61,29 @@ jobs:
 
 ### `author-name`
 
-- **Description**: check committer author name
+- **Description**: check committer author name.
 - Default: 'true'
 
 ### `author-email`
 
-- **Description**: check committer author email
+- **Description**: check committer author email.
 - Default: 'true'
 
 ### `commit-signoff`
 
-- **Description**: check committer commit signature
+- **Description**: check committer commit signature.
 - Default: 'true'
 
+### `merge-base`
+
+- **Description**: check current branch is rebased onto target branch.
+- Default: 'false'
+
+> [!IMPORTANT]
+> `merge-base` is an experimental feature. by default it's disable.
+> 
+> To use this feature, you need fetch all history for all branches by setting `fetch-depth: 0` in `actions/checkout`.
+
 ### `dry-run`
 
 - **Description**: run checks without failing. exit code is 0 otherwise is 1.
@@ -79,18 +91,18 @@ jobs:
 
 ### `job-summary`
 
-- **Description**: display job summary to the workflow run
+- **Description**: display job summary to the workflow run.
 - Default: 'true'
 
 ### `pr-comments`
 
-- **Description**: post results to the pull request comments
+- **Description**: post results to the pull request comments.
 - Default: 'false'
 
 > [!IMPORTANT]
-> `pr-comments` is an experimental feature. To use it you need to set `GITHUB_TOKEN` in the GitHub Action.
+> `pr-comments` is an experimental feature. by default it's disable. To use it you need to set `GITHUB_TOKEN` in the GitHub Action.
 >
-> This feature currently doesn’t work with forked repositories. For more details, refer to issue [#77](https://github.com/commit-check/commit-check-action/issues/77)
+> This feature currently doesn’t work with forked repositories. For more details, refer to issue [#77](https://github.com/commit-check/commit-check-action/issues/77).
 
 Note: the default rule of above inputs is following [this configuration](https://github.com/commit-check/commit-check/blob/main/.commit-check.yml), if you want to customize just add your `.commit-check.yml` config file under your repository root directory.
 
diff --git a/action.yml b/action.yml
index 531acb4..d23acfc 100644
--- a/action.yml
+++ b/action.yml
@@ -25,6 +25,10 @@ inputs:
     description: check committer commit signature
     required: false
     default: true
+  merge-base:
+    description: check current branch is rebased onto target branch
+    required: false
+    default: false
   dry-run:
     description: run checks without failing
     required: false
@@ -57,6 +61,7 @@ runs:
         AUTHOR_NAME: ${{ inputs.author-name }}
         AUTHOR_EMAIL: ${{ inputs.author-email }}
         COMMIT_SIGNOFF: ${{ inputs.commit-signoff }}
+        MERGE_BASE: ${{ inputs.merge-base }}
         DRY_RUN: ${{ inputs.dry-run }}
         JOB_SUMMARY: ${{ inputs.job-summary }}
         PR_COMMENTS: ${{ inputs.pr-comments }}
diff --git a/main.py b/main.py
index eb0af9c..91d2246 100755
--- a/main.py
+++ b/main.py
@@ -16,6 +16,7 @@
 AUTHOR_NAME = os.getenv("AUTHOR_NAME", "false")
 AUTHOR_EMAIL = os.getenv("AUTHOR_EMAIL", "false")
 COMMIT_SIGNOFF = os.getenv("COMMIT_SIGNOFF", "false")
+MERGE_BASE = os.getenv("MERGE_BASE", "false")
 DRY_RUN = os.getenv("DRY_RUN", "false")
 JOB_SUMMARY = os.getenv("JOB_SUMMARY", "false")
 PR_COMMENTS = os.getenv("PR_COMMENTS", "false")
@@ -32,6 +33,7 @@ def log_env_vars():
     print(f"AUTHOR_NAME = {AUTHOR_NAME}")
     print(f"AUTHOR_EMAIL = {AUTHOR_EMAIL}")
     print(f"COMMIT_SIGNOFF = {COMMIT_SIGNOFF}")
+    print(f"MERGE_BASE = {MERGE_BASE}")
     print(f"DRY_RUN = {DRY_RUN}")
     print(f"JOB_SUMMARY = {JOB_SUMMARY}")
     print(f"PR_COMMENTS = {PR_COMMENTS}\n")
@@ -45,11 +47,12 @@ def run_commit_check() -> int:
         "--author-name",
         "--author-email",
         "--commit-signoff",
+        "--merge-base",
     ]
     args = [
         arg
         for arg, value in zip(
-            args, [MESSAGE, BRANCH, AUTHOR_NAME, AUTHOR_EMAIL, COMMIT_SIGNOFF]
+            args, [MESSAGE, BRANCH, AUTHOR_NAME, AUTHOR_EMAIL, COMMIT_SIGNOFF, MERGE_BASE]
         )
         if value == "true"
     ]