Heatwaves are significant environmental hazard which can cause increased deaths and emergency hospital admissions, particularly among vulnerable groups such as elderly people, young children and patients with chronic diseases. As the climate change continues, the frequency, intensity, duration and extent of heatwaves are likely to increase in the future. Under the control of the subtropics high in summer, the Jiangsu-Zhejiang-Shanghai Region, as one of the most advanced economic and most densely populated places, has become the frequent zone of summer heatwaves in our country. Based on the summer (from June to August) daily highest temperature data of 26 meteorological stations and the indexes chosen on the significantly increase in mortality, this paper conducted a statistical analysis on the temporal-spatial distribution characteristics of days, frequency and intensity of heatwaves in Jiangsu-Zhejiang-Shanghai Region from 1961 to 2010. The results show that Jiangsu-Zhejiang-Shanghai Region is a high-risk areaof heatwaves in our country, where the heatwaves weather exist significantly geographical differences. The high values of the heatwaves day numbers, frequency and intensity located in the middle and southwest of Jiangsu Province and west of Zhejiang Province. The tendencies of average heatwaves days frequency and intensity in Jiangsu-Zhejiang-Shanghai Region are very similar. Generally, the heatwaves days, frequency and intensity showed a trend of decrease (weaken) from the 1960 s to the early 1980 s, and showed a trend of increase (strengthen) from the late 1980 s to the first decade of this century. Overall, the days, frequency and intensity of heatwaves in Jiangsu-Zhejiang-Shanghai Region have significantly increased and strengthened. Nearly 50 years, there showed the decline of the tendency coefficient for the heatwaves days, frequency and intensity in the middle of Jiangsu Province, which was the high-value region of the heatwaves, and showed rise of the tendency coefficient in the south of Jiangsu Province and east of Zhejiang Province, which was the low-value region of the heatwaves. So, the heatwaves weather in summer displayed a trend of gradually shifting to the south over the Jiangsu-Zhejiang-Shanghai Region. Heatwaves, affected by global warming and urban heat island, gradually intensified during the last 50 a in Jiangsu- Zhejiang-Shanghai Region. The study followed should pay close attention to the heatwaves formation and change mechanism, such as the impaction of urban heat island and subtropics high on the temporal-spatial distribution of heatwaves.