Abstract: Based on themodel of carrying soil failure under the condition of rainfal,l the influence of rainfallon the stability ofcarrying soilduring the afforestation ofa slopewas investigated. The research indicates that the stability of carrying soil is closely related to the character of rainfal,l the gradientof an afforested slope, the characteristics of slope surface, the feature of soil and the thickness of soi.l When the gradientof a slope to be afforested is large, a thin soil layerwill be necessary in order to maintain the stability of carrying soi.l