diff --git a/.gitignore b/.gitignore
index 4c49bd7..64fed38 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .env
+test
diff --git a/README.md b/README.md
index 0531574..be0e9d6 100644
--- a/README.md
+++ b/README.md
@@ -84,3 +84,29 @@ jobs:
           target_branch: 'develop'
           github_token: ${{ github.token }}
 ```
+
+### Check merged branch
+
+Assign label to pull request merged in another branch.
+
+Run workflow on staging branch, this workflow check if the `GITHUB_SHA` have a pull request, and assign the label 'merged-in-staging' and create a check-run in the merged commit.
+
+```yaml
+name: Set label on merged branch
+on:
+  push:
+    branches:
+      - 'staging'
+jobs:
+  merge-branch:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+
+      - name: check merge in staging
+        uses: devmasx/merge-branch@v1.3.1
+        with:
+          type: 'merged-label'
+          label_name: merged-in-staging
+          github_token: ${{ github.token }}
+```
diff --git a/lib/constans.rb b/lib/constans.rb
new file mode 100644
index 0000000..3a738d6
--- /dev/null
+++ b/lib/constans.rb
@@ -0,0 +1,5 @@
+module Constans
+  TYPE_LABELED = "labeled".freeze
+  TYPE_NOW = "now".freeze
+  TYPE_MERGED_LABEL = "merged-label".freeze
+end
diff --git a/lib/index.rb b/lib/index.rb
index ab8d379..117321e 100644
--- a/lib/index.rb
+++ b/lib/index.rb
@@ -1,6 +1,10 @@
+# frozen_string_literal: true
+
 require 'json'
 require 'octokit'
+require_relative './constans'
 require_relative './services/merge_branch_service'
+require_relative './services/check_merged_branch_service'
 
 def presence(value)
   return nil if value == ""
@@ -13,18 +17,26 @@ def presence(value)
 @github_token = presence(ENV['INPUT_GITHUB_TOKEN']) || presence(ENV['GITHUB_TOKEN'])
 
 inputs = {
-  type: presence(ENV['INPUT_TYPE']) || MergeBrachService::TYPE_LABELED, # labeled | comment | now
+  type: presence(ENV['INPUT_TYPE']) || Constans::TYPE_LABELED,
   label_name: ENV['INPUT_LABEL_NAME'],
   target_branch: ENV['INPUT_TARGET_BRANCH']
 }
 
-MergeBrachService.validate_inputs!(inputs)
-service = MergeBrachService.new(inputs, @event)
-
-if service.valid?
-  @client = Octokit::Client.new(access_token: @github_token)
-  @client.merge(@repository, inputs[:target_branch], @head_to_merge)
-  puts "Finish merge branch to #{inputs[:target_branch]}"
+@client = Octokit::Client.new(access_token: @github_token)
+if inputs[:type] == Constans::TYPE_MERGED_LABEL
+  LabelMergedBranchService.new(@client, {
+    sha: @head_to_merge,
+    label_name: inputs[:label_name],
+    repo: @repository
+  }).run
 else
-  puts 'Skip'
+  MergeBrachService.validate_inputs!(inputs)
+  service = MergeBrachService.new(inputs, @event)
+
+  if service.valid?
+    @client.merge(@repository, inputs[:target_branch], @head_to_merge)
+    puts "Finish merge branch to #{inputs[:target_branch]}"
+  else
+    puts 'Skip'
+  end
 end
diff --git a/lib/services/check_merged_branch_service.rb b/lib/services/check_merged_branch_service.rb
new file mode 100644
index 0000000..8666196
--- /dev/null
+++ b/lib/services/check_merged_branch_service.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+class CheckMergedBranchService
+  CHECK_BASE_NAME = "merge-branch"
+
+  def initialize(client, sha:, label_name:, repo:)
+    @client = client
+    @sha = sha
+    @label_name = label_name
+    @repo = repo
+  end
+
+  def run
+    if pull_request
+      create_label
+    else
+      puts "Not Pull request found"
+    end
+    create_check_run
+  end
+
+  def commit_sha
+    return @commit_sha if @commit_sha
+
+    all_commits = @client.commits(@repo, @sha)
+    if is_merged_commit?(all_commits.first)
+      @commit_sha = all_commits[1].sha
+      # puts "Commit sha (no merge) #{@commit_sha}"
+    else
+      @commit_sha = @sha
+    end
+  end
+
+  def pull_request
+    return @pull_request if @pull_request
+
+    all_commits = @client.commits(@repo, @sha)
+    pull_requests = @client.pull_requests(@repo, :state => 'open')
+    @pull_request = pull_requests&.find{ |item| commit_sha == item.head.sha }
+  end
+
+  def create_label
+    puts "Create label #{@label_name} on #{pull_request.number}"
+    @client.add_labels_to_an_issue(@repo, pull_request.number, [@label_name])
+  end
+
+  def create_check_run
+    url = "/repos/#{@repo}/check-runs"
+    @client.post(url, {
+      name: "#{CHECK_BASE_NAME}: #{@label_name}",
+      head_sha: commit_sha,
+      status: 'completed',
+      started_at: Time.now.iso8601,
+      conclusion: "success",
+      output: {
+        title: "#{CHECK_BASE_NAME}: #{@label_name}",
+        summary: "#{CHECK_BASE_NAME}: #{@label_name}",
+        annotations: []
+      }
+    })
+  end
+
+  def is_merged_commit?(commit)
+    commit.parents.count >= 2
+  end
+end
diff --git a/lib/services/merge_branch_service.rb b/lib/services/merge_branch_service.rb
index cfe7b41..7b83256 100644
--- a/lib/services/merge_branch_service.rb
+++ b/lib/services/merge_branch_service.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+require_relative '../constans'
+
 class MergeBrachService
   attr_reader :inputs, :event
-
-  TYPE_LABELED = "labeled".freeze
-  TYPE_NOW = "now".freeze
+  include Constans
 
   def self.validate_inputs!(target_branch:, type:, label_name:)
     raise "Invalid type" unless [TYPE_LABELED, TYPE_NOW].include?(type)