Abstract: Based on daily temperature data (minimum, maximum) of 83 stations, spatial and temporal changes of extreme temperature events over arid region of northwest China were analyzed and predicted for the period 1961~2012, so as to better service for the ecological protection and agricultural production. (1) From the trend of time, the average minimum/maximum temperature(TMINmean/TMAXmean) had an ascending tendency, especially after 1981, winter and autumn are the most significant; Extra-minimum air temperature (TNn) and extra-maximum air temperature (TXx) had an raising trend, warm days (TX90p) and nights(TN90p) had an increasing trend, it was worthwhile to note that the most significant change above was the night indices of summer; Additionally, mutation were found firstly in winter during 1979~1986. Apart from the variation rate of TNn in summer, the seasonal and seasonal variations of the other indices in the period 2013-2020 are consistent with the increase and decrease in the period 1961-2012. (2)From spatial distribution, the maximum number of days (nights), the minimum number of cold days (nights) were in the Northern Division, while Inner Mongolia - Ningxia Division of the fastest rate of change; 2013-2020, Xinjiang In the Inner Mongolia - Ningxia and Nanjiang sub - regions, the extreme minimum (high) temperature extremes of the summer days decreased drastically (increased) in the cold days and cold nights.