Abstract: Based on the daily minimum air temperature at five national meteorological observation stations over eastern Hexi Corridor during 1961-2017,the spatio-temporal variations and cooling ranges of cold air at five levels were statistically analyzed,and the characteristics of local extreme cold wave were obtained by applying monthly mean 500 hPa geopotential height field and wind field circulation data from NCEP.The results showed that:（1）The annual average days of cold air were the most in level Ⅰ,basically close in level Ⅴ and Ⅳ,and the least in level Ⅲ.For level Ⅰ,it was less in northern desert area and more in central plain area,and the other four levels were basically similar in which,the northern desert areas were more.The time distribution of level Ⅱ,Ⅳ and Ⅴ was the most in spring April-May but the least in summer;the Ⅲ level was concentrated in summer from July to August;the frequency of level Ⅰ was close in each month but slightly more in August.（2）The linear trend of annual cooling days decreased obviously in level V and Ⅳ,but showed weak linearity in level Ⅰ to Ⅲ with slightly increase in level Ⅰ and Ⅱ.The inter-decadal variation of the average annual cooling frequency was not significant,and the whole decreased first and then increased.（3）The seasonal variation of average cooling range was only obvious in level Ⅴ,similar to level Ⅳ,while the maximum cooling range of level Ⅰ to Ⅲ was in spring,autumn and summer,respectively;the maximum temperature drop of level Ⅴ at 24 h,48 h and 72 h was 9.9,12.2 and 14.3 ℃,respectively.（4）There were 12 extreme years in cold wave,the difference of cold wave days in more（less） years was the biggest in October but smaller in summer.During the positive-anomaly cold wave years,the 500 hPa geo-potential height field over eastern Hexi Corridor was controlled by northwest airflow with a negative anomaly height center,and the polar dry and cold air transport in front of the Urals Ridge was conducive to the occurrence of cold wave.During the negative-anomaly cold wave years,it was controlled in straight westerly with obvious positive anomaly height,as cold air activity was less,cooling disaster weather hardly occurred.