Java tutorial
//package com.java2s; import android.content.Context; import android.content.Intent; import android.net.Uri; public class Main { /** * Dial a ussd code */ public static void dailNumber(Context context, String telNo) { String ussdCode = telNo + Uri.encode("#"); context.startActivity(new Intent("android.intent.action.CALL", Uri.parse("tel:" + ussdCode))); } }