Abstract: Based on the daily temperature observations of 166 national basic stations and the circulation indexes of the western Pacific subtropical high,we have calculated the frequency,duration,intensity of heat waves.With the method of trend analysis,and Mann-Kendall test, etc,the spatial and temporal characteristics of heat waves in Yangtze River Basin from 1961—2010 have been explored,along with its spatial variation trends.The results show that the frequency,duration,intensity of heat waves in Yangtze River Basin all show an distinct decadal revolution of decreasing—increasing,decreasing in the 1960s to 1980s,while increasing from the 1990s up to now,the frequency,duration,and intensity of heat waves presented a detectable increase with the linear trend 0.06/10a,0.03 d/10a,0.29℃·d/ 10a,respectively,and the ridge line and the north side of the western Pacific subtropical high show a significant correlation with the heat waves;spatially,the frequency,duration,intensity of heat waves presents the feature that there are more occurrence in south of Yangtze River basin than that in the region of north and gradually decreases from southeast to northwest,meanwhile the heat waves are mainly centered on the middle east Dongting Lake Basin to the Poyang Lake River Basin,as well as the upper and middle reaches of the Yangtze River;except from the east Hanjiang Basin and the center of the Dongting Lake basin.The variation trend of heat waves presents an increasing trend in other places,mainly in the east Taihu Basin,southeast Poyang Lake Basin,along with the lower and middle reaches of the Yangtze River.