According to the definition of heat wave by China Meteorological Administration, geographical zones, and grading standard of humidity in heat wave days, a heat wave event is defined to be a process when the surface maximum air temperature equal to or higher than 35 °C in three consecutive days in the study.The spatial-temporal distribution and variation trend of the number of the summertime dry/wet heat wave (HW) days from 1960 to 2018 are investigated using the data from 476 meteorological stations in China. It is found that the number of the summertime HW days decreases from Southeast China to Northwest China (except for XinJiang) and the Jiangnan region experiences the most frequent HW events (about 15 d per year). The evaluation results of temperature-humidity index (THI) and the comfort index of human body (ICHB) identifies the worst environmental comfort level during HW over the Jianghuai region, where the adverse effects of HW on human body are more significant. The sea breeze can significantly reduce the afternoon air temperature and alleviate the impact of the summertime HW in the coastal areas, and the number of HW days in the coastal stations is less than that in the adjacent inland stations. Except for the Huanghuai region, the number of HW days increases at most stations in China and the increasing trend is significant (1～5 d•(10 a) -1, α=0.05) in Jiangsu, the coastal areas of Zhejiang, Guangdong, Chongqing, Hainan, Xinjiang, and the east of Guangxi; the number of wet HW days increases significantly by 1～5 d•( 10 a) -1 over the east and southeast coast of China; the number of dry HW days also increases significantly (α=0.01) in Zhejiang, the north part of Jiangxi, Gansu, and Xinjiang. The summertime HW events have been more frequent in China since 1990 the number of dry HW days is more from 2000 to2009, while the proportion of strong wet HW days have increased since 2010.