Presently, except for the availability of international flights between Kathmandu and Lhasa, there is no direct flight to Tibet from United States, Singapore, UK, Australia, Canada, India, Hong Kong or other international countries. The global tourists need to transfer in Beijing, Shanghai, Guangzhou, Chengdu, Chongqing, Xian, Kunming, Shangri-La, Xining, Nanjing, or Xiamen, so as to arrive in Lhasa by flight.
The cost of flights to Tibet is considerably higher than the rest of China, hardly with discount or cheap flight tickets available even during the off season, which is largely due to the huge demand. So it's better to book Tibet air tickets in advance.
"Flights to Tibet"