International plane tickets in Xining can only be issued at one place in Xining. This can be done at the ticket office on Bayilu. They are only open during normal working hours. You can pay in cash and pay with your chinese bank card.
You can of course also contact travel agents in other cities in China. Reserve/book you tickets and then pay by bringing your cash to a bank in Xining to be send to the travel agent somewhere else.
You don’t need any plane ticket anymore to check in at the airport. Just your passport is enough.
You can also first phone or email them:
Email address and mobile of one of the ladies working there:
firstname.lastname@example.org (so I guess that her QQ is also an option). Chinese language only.
Mobile: 13897201275 Chinese only
Let me know when the above info is incomplete and incorrect, so that I can change it here.
A: Ticket Office/ airport office at Bayilu (about 400 mtr west of Kangle junction)
祥云山水酒店 (Xiángyún shānshuǐ jiǔdiàn): Departure point of the Airport bus (northwest corner of Kangle junction)