diff --git a/java/src/HelloWorld.java b/java/src/HelloWorld.java
index f064af0..aade241 100644
--- a/java/src/HelloWorld.java
+++ b/java/src/HelloWorld.java
@@ -9,5 +9,8 @@ class HelloWorld {
     public static void main(String[] args) {
         String output = HelloWorld.hello("fanruan");
         System.out.println(output);
+
+        int r = MyMath.add(50, 32);
+        System.out.println(r);
     }
 }
\ No newline at end of file
diff --git a/java/src/MyMath.java b/java/src/MyMath.java
new file mode 100644
index 0000000..bb5dabd
--- /dev/null
+++ b/java/src/MyMath.java
@@ -0,0 +1,9 @@
+/**
+ * @author richie
+ * @version 10.0
+ * Created by richie on 2019-08-01
+ */
+public class MyMath {
+
+    public static native int add(int a, int b);
+}