With the global climate warming, the research on regional extreme climate changes has assumed particular significance. Based on climatological statistical methods and the meteorological data of 107 stations over arid areas of Northwest China during the period of 1961-2010, the spatial and temporal characteristics and laws of the minimum and maximum temperature were analyzed. The results show that the extreme minimum and maximum temperature had undergone an asymmetric growth. The warming trend of extreme minimum temperature was obviously higher than that of the maximum temperature, which resulted in a different decreasing trend, especially in Tianshan Mountains. The extreme minimum temperature of arid areas of Northwest China showsed a nearly zonal distribution and the temperature gradient variation was significant. The warm centers of extreme maximum temperature were located in the Junggar Basin and Tarim Basin. Since the late 20 th century, the extreme minimum and maximum had takn on a significant warming trend. The extreme minimum temperature exhibited an anomalous cold phenomenon in 1967 and the extreme maximum temperature brought about an anomalous warm phenomenon in 1997 and 2000 respectively.