The spatial distribution and time series of diurnal temperature range(DTR) in China are analyzed using the daily temperature data from 1950 to 2001.The relations among the maximum and minimum temperature and the mean temperature are discussed for their possible influence on DTR.The analyzed results show that DTR was decreased in China in the last 50 years.The average decrease of DTR in the high latitude is larger than that of in low latitude.The DTR in the same region or different regions have the different features in seasonal changes.In the northern China the maximum decrease of DTR is in winter,and then spring and autumn,the minimum,is in summer.In Huang-huai and Yangtze River reaches the maximum decreases of DTR are in summer and spring.In South China the maximum of DTR is in winter.On the average,the DTR is decreasing,and this decreasing is more significant in high and middle latitude regions than in low latitude.For the regions that are in the same latitudinal zone the trends of DTR changes are different because of different geographical backgrounds.The DTR has obvious seasonal change and shows a fast decrease in winter and slow decrease in summer in most regions of China,especially in Qinghai-Xizang Plateau and Xinjiang the features of DTR change are quite different from those in the eastern China.