Abstract: The paper aims to understand the heat injury of tea in southern Zhejiang, and better serve agricultural production. According to the daily average temperature, daily maximum air temperature and daily mean relative humidity dataset from 7 observation stations in southern Zhejiang during 1971-2017, based on the statistical days of heat injury of tea according to the heat injury grade index for tea plant, we analyzed the temporal and spatial characteristics of heat injury days of tea by using the trend analysis method and the Mann-Kendall test. The results showed that: the mean heat injury days of tea in southern Zhejiang was 5.2 d/a, the highest was in Lishui (12.9 d/a), and the lowest was in Qingyuan (1.1 d/a), and the highest occurrence probability in late July; the heat injury days of tea showed a significant increasing trend with the rate at 1.9 d/10a, mutated in about 2000, and the increasing trend was the most significant in the early 21th century. Lishui was the most obvious area occurring heat injury of tea in southern Zhejiang, and climate trend rate was 4.7 d/10 a, the mutation of heat injury of tea occurred in 1993 in Lishui, and the increasing trend was the most significant at the beginning of 2003. Therefore, the risk of heat injury of tea will obviously increase.