Abstract: This paper aims to calculate and analyze the precipitation, precipitable water(PW)and precipitation conversion efficiency in the Bayingolin Prefecture, Xinjiang, China by using the empirical formula of atmospheric total PW. The data of monthly mean precipitation and water vapor pressure used in this paper were acquired from 11 meteorological stations in the Bayingolin Prefecture from 1965 to 2014. The results showed as follows:(1) The monthly precipitation, precipitable water and precipitation conversion efficiency in different areas of Bayingolin Prefecture had consistently a unimodal distribution.(2) The maximum amount of precipitation in all areas of Bayingolin appeared in summer, the northern mountains area had the most with 164.2 mm and accounted for 68.9% of annual precipitation, and the southern region had the least with 21.7 mm and accounted for 70.9% of annual precipitation, while the minimum precipitation was in winter with 1.5-6.1 mm. In general, the precipitation was less in the 1960s, and the most was in the two decades of the 1980s and 1990s. The precipitation displayed a reducing trend from north to south and from east to west.(3) The maximum amount of precipitable water in all areas of Bayingolin appeared in summer, the Yanqi Basin had the most with 1 018.0 mm,the northern mountains area had the least with 607.7 mm, while the minimum precipitable water was in winter, the northern mountains area had only 113.5 mm, the other area ranged form 259.6 to 287.2 mm. The precipitable water of all areas has been increasing in the near 50 years. Yanqi Basin increased mostly and the southern areas followed. The precipitable water of four seasons also had increased, especially in summer.(4) The maximum amount of precipitation conversion efficiency in all areas of Bayingolin appeared in summer, that of the northern mountains area was 27.0%, but the southern area was only 2.3%. The precipitation conversion efficiency of the northern mountains area was the largest in four seasons of Bayingolin.

Key words: precipitation, precipitable water, precipitation conversion efficiency, climate change, Bayingolin