Hi, Im going in May from Xian to Jiuzhaigou. Is this peak period for flights? Where can i Buy the tickets?

According to the previous records, it is the peak season for direct flights.
But this year's flight schedule is not publiched yet, the real situation is hard to tell. So it is suggested to keep attention on the online information. You can search the flight timetable on the Flight Section on this website. Also you can buy the tickets on the website directly!