Based on the observed data of precipitation in Guangdong Province, the characteristics of spatiotemporal variations of heavy rain in early rainy season (April-June) were studied. The results show: (1) The spatial distribution of heavy rain frequency is consistent with the rainfall and has obvious regional characters. The heavy rain frequency can represent the drought and flood trend in the early rainy season. By REOF method, the heavy rain distribution can be divided into 4 regions: East Guangdong, the Pearl River Delta region, Northwest Guangdong and Leizhou Peninsula. (2) The main periods in the frequency variation of heavy rain are 2-3 a and 6-10 a. The period of each region has shortened since 1985, with the main period of 4-5 a. (3) The frequency of heavy rain in the Pearl River Delta and the region south to it has an increasing trend, which is more obvious in the center of Peal River Delta region, and passed a confidence level test at 0.05. The most obvious change happened in June.