By flight-There are about 9 direct flights from Xian to Lhasa, the earliest departs at 06:00 while the latest departs at 16:25; The whole journey takes about 3 hours with a full ticket price of RMB2300.
By Train - There are 2 trains passing by Xian Z265(09:45-16:10) & Z165 (11:24-19:35), arriving in Lhasa the next day.