Rainfall is one of the main driving forces of soil erosion. In order to explore the spatial-temporal variations of rainfall erosivity with different magnitudes, the 24 h rainfall data of 42 meteorological stations in Chongqing and its surrounding stations from 1960 to 2017 were selected so as to calculate the R value by the daily rainfall erosivity model. And the spatial-temporal variation of different magnitudes rainfall erosivity in different time scales were analyzed by utilizing the climate tendency rate, variation coefficient and ordinary Kriging. The results showed that: (1) The average annual R value of Chongqing was 5 751.55 (MJ·mm)/(hm²·h·a) in 58 a, and the variation coefficient of the average annual R value was 0.19, which between 0.1 and 1, belonging to a medium variation. (2) The order of contribution rate of rainfall erosivity of different magnitudes to annual R value was heavy rain (34.82%)＞rainstorm (30.53%)＞moderate rain (23.93%)＞downpour (10.53%), and the increasing trend of downpour erosivity was dominant in annual rainfall erosivity. (3) The distribution of annual R value was extremely uneven, with 54.19% concentrated in summer and only 0.91% in winter. (4) The annual and each magnitude rainfall erosivity showed a decreasing trend from east to west. This study clarifies the periods and areas with high possibility of soil erosion, protective measures are supposed to take to control soil erosion according to local conditions.