Based on the meteorological data from 113 surface and 24 radiosonde stations in Northwest China from 1960 to 2015,the empirical formula was established between precipitable water (P_(WV)) and surface vapor pressure,and theP_(WV) in Northwest China was calculated.With the methods such as inverse distance weighted,Mann-Kendall test and Morlet wavelets,the temporal and spatial distribution ofP_(WV) and its relations with other meteorological elements were analyzed.The results showed thatP_(WV) has increased in last 56 years with the increasing rate of 0.11 mm per decade,and the obviously unimodal types can beexamined for the monthly variations.The highP_(WV) area is mainly in the east of Northwest China,and the middle area of Northwest China usually presents a low value.TheP_(WV) in most parts of Northwest China has increased,which is obvious in southern Shaanxi,southeastern Gansu,northwestern Qinghai and Xinjiang.The annual averageP_(WV) in Northwest China shows an obvious mutation around 1983 and a periodical change with primary period of approximately 4 years.P_(WV) in Northwest China shows a positive correlation with mean air temperature and relative humidity,and a negative correlation with wind speed.