Abstract: The paper is based on the aircraft-borne data from Sichuan airline during 2006.The authors analysis turbulence produces in the cruising phase distribution on 14 western routes which are around the airport of Chengdu.The research points out that the Tibet area occurs the largest probability of turbulence;the aircraft turbulence mainly appear in spring and the fall occur very few;aircraft turbulence mainly distribute between 7000m and 10000m altitude range;middle-light is the most high probability turbulence level,follow is light level and the probability of strong level is the most minimum.