Well, there is no answer within 2 days. Meanwhile I found a way to access others calender. I want to share my solution so that other can get a helsp:-
ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010);
service.Credentials = new WebCredentials();
Mailbox principle = new Mailbox("usedr@domain.com");
CalendarFolder calendar2 = CalendarFolder.Bind(service, new FolderId(WellKnownFolderName.Calendar, principle), new PropertySet());
// Retrieve a collection of appointments by using the calendar view.
FindItemsResults<Appointment> appointments2 = calendar2.FindAppointments(cView2);
appointments2 should have all the calender meeting.