This study is entitled «Analysis of the rainfall aggressiveness on the soils of the N’Zi watershed. The objective is to analyze the importance of precipitation on soil erosion. To achieve the objective, daily, monthly and annual rainfall data on the N’zi watershed were collected over the period 1960 to 2019. The analysis of rainfall risks was possible for the index of erosivity of Arnoldus and Rango-Arnoldus rainfall, to graphical and spatial representations with R software and ArcGIS software. The results of the analysis of the interannual variability of precipitation show that the temporal aggressiveness generally declined during the 1970s. The rainfall aggressiveness indicates on a monthly scale a weak aggressiveness in general and the strongest would be seasonal at the level of the localities of the basin. It highlights three levels of rainfall aggressiveness on an annual scale: very aggressive aggressiveness (32%), less aggressive (48%) and more or less aggressive aggressiveness (20%), at the basin scale. Five (5) classes were distinguished; excess dominance (41%) qualified as high rainfall aggressiveness, dry period (30%) qualified as low rainfall aggressiveness, a minimum period (18%) qualified as very low rainfall aggressiveness, a maximum period (9%) qualified very high rainfall aggressiveness and a normal period (2%) qualified as average rainfall aggressiveness.