diff --git a/diycode-app/src/main/java/com/example/wenwei/diycode/activity/MainActivity.java b/diycode-app/src/main/java/com/example/wenwei/diycode/activity/MainActivity.java
index f9d3e5a..f03121a 100644
--- a/diycode-app/src/main/java/com/example/wenwei/diycode/activity/MainActivity.java
+++ b/diycode-app/src/main/java/com/example/wenwei/diycode/activity/MainActivity.java
@@ -28,6 +28,7 @@
 import com.example.wenwei.diycode.fragment.TopicListFragment;
 import com.example.wenwei.diycode.test.TextFragment;
 import com.example.wenwei.diycode.data.cache.DataCache;
+import com.example.wenwei.diycode.utils.DBManager;
 import com.example.wenwei.diycode_sdk.api.login.event.LogoutEvent;
 import com.example.wenwei.diycode_sdk.api.user.bean.User;
 import com.example.wenwei.diycode_sdk.api.user.bean.UserDetail;
@@ -53,6 +54,10 @@ public class MainActivity extends BaseActivity implements
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setEnableSwipeGesture(false);
+
+        DBManager dbManager = new DBManager(this);
+        dbManager.open();
+        dbManager.close();
     }
 
     @Override
diff --git a/diycode-app/src/main/java/com/example/wenwei/diycode/utils/DBManager.java b/diycode-app/src/main/java/com/example/wenwei/diycode/utils/DBManager.java
new file mode 100644
index 0000000..4936544
--- /dev/null
+++ b/diycode-app/src/main/java/com/example/wenwei/diycode/utils/DBManager.java
@@ -0,0 +1,71 @@
+package com.example.wenwei.diycode.utils;
+
+import android.content.Context;
+import android.database.sqlite.SQLiteDatabase;
+import android.os.Environment;
+import android.util.Log;
+
+import com.example.wenwei.diycode.R;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Created by liwenwei on 6/8/2018.
+ */
+
+public class DBManager {
+
+    private final int BUFFER_SIZE = 400000;
+    private String DB_PATH;
+    private final String DB_NAME = "countries.db";
+
+    private SQLiteDatabase database;
+    private Context context;
+
+    public DBManager(Context context) {
+        this.context = context;
+        DB_PATH = "/data"
+                + Environment.getDataDirectory().getAbsolutePath() + "/"
+                + context.getPackageName();
+    }
+
+    public void open() {
+        database = open(DB_PATH + "/" + DB_NAME);
+    }
+
+    private SQLiteDatabase open(String dbFile) {
+        File file = new File(dbFile);
+        if (!file.exists()) {
+            try {
+                InputStream is = context.getResources().openRawResource(R.raw.countries);
+                FileOutputStream fos = new FileOutputStream(dbFile);
+                byte[] buffer = new byte[BUFFER_SIZE];
+                int len;
+                while ((len = is.read(buffer)) > 0) {
+                    fos.write(buffer, 0, len);
+                }
+
+                is.close();
+                fos.close();
+            } catch (FileNotFoundException e) {
+                Log.e("Database", "File not found");
+                e.printStackTrace();
+            } catch (IOException e) {
+                Log.e("Database", "IO exception");
+                e.printStackTrace();
+            }
+        }
+        SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbFile, null);
+        return db;
+    }
+
+    public void close() {
+        if (this.database != null) {
+            this.database.close();
+        }
+    }
+}
diff --git a/diycode-app/src/main/res/raw/countries b/diycode-app/src/main/res/raw/countries
new file mode 100644
index 0000000..77b56e6
Binary files /dev/null and b/diycode-app/src/main/res/raw/countries differ