diff --git a/.github/workflows/package.yaml b/.github/workflows/package.yaml
new file mode 100644
index 0000000..f0238d2
--- /dev/null
+++ b/.github/workflows/package.yaml
@@ -0,0 +1,41 @@
+name: Export Package
+
+on:
+  pull_request: {}
+  push: { branches: [main] }
+
+env:
+  UNITY_LICENSE: ${{ secrets.UNITY_LICENSE_2020 }}
+
+jobs:
+  build:
+    name: Build UnityPackage
+    runs-on: ubuntu-latest
+    steps:
+      # Checkout
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          lfs: true
+
+      # Cache
+      - name: Cache
+        uses: actions/cache@v2
+        with:
+          path: Library
+          key: Library
+          restore-keys: Library-
+
+      # Build
+      - name: Build .unitypackage
+        uses: game-ci/unity-builder@v2
+        with:
+          unityVersion: 2020.3.8f1
+          buildMethod: MackySoft.PackageTools.Editor.UnityPackageExporter.Export
+
+      # Upload
+      - name: Upload .unitypackage
+        uses: actions/upload-artifact@v2
+        with:
+          name: Unity Package
+          path: Build
\ No newline at end of file
diff --git a/Assets/MackySoft/MackySoft.SerializeReferenceExtensions/package.json b/Assets/MackySoft/MackySoft.SerializeReferenceExtensions/package.json
new file mode 100644
index 0000000..73af759
--- /dev/null
+++ b/Assets/MackySoft/MackySoft.SerializeReferenceExtensions/package.json
@@ -0,0 +1,10 @@
+{
+	"name": "com.mackysoft.serializereference-extensions",
+	"displayName": "SerializeReference Extensions",
+	"version": "1.0.1",
+	"unity": "2019.4",
+	"description": "Provide popup to specify the type of the field serialized by the [SerializeReference] attribute in the inspector.",
+	"keywords": [ "SerializeReference", "Editor" ],
+	"license": "MIT",
+	"dependencies": {}
+}
\ No newline at end of file
diff --git a/Assets/MackySoft/MackySoft.SerializeReferenceExtensions/package.json.meta b/Assets/MackySoft/MackySoft.SerializeReferenceExtensions/package.json.meta
new file mode 100644
index 0000000..a5d9dfe
--- /dev/null
+++ b/Assets/MackySoft/MackySoft.SerializeReferenceExtensions/package.json.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: eda2c3e2d06229b4bb2c21d541f92f49
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: