This paper investigated the spatial and temporal distribution of precipitation during 1971 to 2011 in Nagqu Prefecture of Northern Tibet Plateau,China based on the monthly precipitation and the annual number of precipitation days at 6 meteorological stations and climatic statistic methods, including linear tendency evaluation,multistage curve simulation and the Mann - Kendall test. Results show that annual precipitation exhibits increasing trend in the past 41 years which experienced two periods from less precipitation to more precipitation. The increase of precipitation in summer is quite obvious with 6. 48 to 20. 40 mm increment per decade while the variation is pretty small in winter. The interannual distribution of number of days with daily precipitation larger than 0. 1 mm is basically has same variation with the annual precipitation. The spatial distribution of precipitation decreases from the southeast to the northwest parts of Tibet. The precipitation start to increase from 1996 at each meteorological stations and it has greater possibility of abrupt climate change in 1999.