Let say you have a list view activity in a separate project and is defined as library and it's main activity is "com.ls.list.MyActivity" t he proper way is to add the activity in the main project manifest file <activity android:name="com.ls.list.MyActivity" /> then create intent as usual Intent intent =new Intent(this, MyActivity.class); startActivity(intent); another way which does not need the manifest changes inside the main project's activity just write this simple code Intent intent = new Intent(android.content.Intent.ACTION_VIEW); intent.setComponent(new ComponentName("com.ls.list","com.ls.list.MyActivity")); startActivity(intent);