public class FragmentA extends Fragment {
  private onButtonPressListener mListener;

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_linmo_select_beitie, container, false);
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
      @Override
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        mListener.onOKButtonPressed(selectedBeitie);
      }
    });

    return view;
  }

  @Override
  public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
      mListener = (onButtonPressListener) activity;
    } catch (ClassCastException e) {
      throw new ClassCastException(activity.toString() + " must implement onOkButtonPressed");
    }
  }

  public interface onButtonPressListener {
    void onOKButtonPressed(LinmoBeitieItem item);
  }
}

public class MainActivity extends Activity implements FragmentA.onButtonPressListener {
  @Override
  public void onOKButtonPressed(LinmoBeitieItem item) {
    FragmentB fragmentB = （FragmentB）getFragmentManager().findFragmentById(R.id.container);
    fragmentB.onBeitieSelected(item);
  }
}

public class FragmentA extends Fragment {
  public void onBeitieSelected(LinmoBeitieItem item) {
    // ...
  }
}