By using TBB data, NCEP/NCAR reanalysis data and precipitation assimilation data from TRMM(3B42) and rain gauge data, the influence of landing path, impact strength, cold air intrusion and atmospheric seasonal changes of 25 processes of Bay of Bengal storms from 1998 to 2010 on precipitation over the plateau region were classified statistical analyzed. The results show that: (1) The Bay of Bengal Storm is the important weather system affected rainfall over the plateau area. Its most active period focused on the annual May and October to November. (2) The landing path of Bay of Bengal storm can be divided into three categories, NE (northeast), NW (northwest) and W (west) paths. Storms from NE path landing with maximal impact rainfall over Yunnan-Guizhou Plateau and the southeast of the Qinghai-Xizang Plateau. Storms from NW path landing mainly affected the south of the Qinghai-Xizang Plateau. Storms from W path landing with minimal impact on the Qinghai-Xizang Plateau. (3) Storm from NE path landing with TS (tropical storm) intensity can bring more precipitation for plateau than the H (hurricane) intensity, and to NW path, the H intensity can bring more precipitation for plateau that the TS. (4) For storms from NE path landing, when mated with cold air over Yunnan-Guizhou Plateau, the precipitation can reach more than 15 mm, even 50 mm or more in some areas. But, when no cold air, the precipitation does not exceed 15 mm. (5) Seasonal atmospheric circulation (steering flow) and water vapor transport (strength) and tropical cyclone formation conditions are different between two storms activities peak periods in May and October to November. The differences lead to different scale precipitation on the plateau.