Abstract: Heat wave has a significant impact on human health. The on-going climate change is predicted to yield a growing number of heat waves which will be aggravated in both intensity and frequency. In this paper, the increasing incidence of mortality and morbidity of many diseases such as fever, heat stroke, cardiovascular diseases, respiratory diseases, mental illness, some infectious diseases and others during heat wave was reviewed, especially the elderly, children and patients with some chronic diseases. This effect was also related with heat wave itself, socioeconomic factors, behavioral factors and air pollution. In addition, there were "lag effects and harvesting". The study methods were also summarized briefly. Most of the study methods focused on statistical methods, but animal experiments and crowd experimental studies were few, so more attention should be paid to influences that heat wave makes on various types of human diseases by experimental methods.