The sensitivity of 139 isolates of Blumeria graminis f. sp. tritici to temperature was tested by using detached leaf segment method at 6 different temperatures which were 18,22,23,24,25 and 26 ℃,respectively. These isolates were sampled from 10 provinces or cities such as Sichuan, Beijing, Gansu, Henan, Zhejiang, Shaanxi, Qinghai, Shandong, Xinjiang and Yunnan in 2012. The results showed that the mean ET_(50)of tested isolates was 23.14 ℃ . The highest and the lowest ET_(50) of isolates were 24.46 and 21.34℃,respectively. ET_(50) values of 58.76% isolates were between 23℃ and 24 ℃,only 2.03% isolates were higher than 24 ℃ . The results of frequencies distribution of ET_(50) values of the isolates with different sensitivity to temperatures revealed that the pathogen population in natural environment had been selected by temperature pressure. These results will provide basis for predicting effects of global climate change on wheat powdery mildew.