Interflow is an important component of the flow on slopes with purple soil , and is determined compre-hensively by rainfall , slope feature , soil depth and cultivation regime. Simulated rainfall was used to study the mechanism of interflow on slope cropland of purple soil. Results show that cultivation can improve soil physical structure and induce a higher probability for interflow occurrence. Shallow soil depth on slope cropland dominates interflow occurrence , and flat slope generates interflow more easily than steep slope. Rainfall intensity has a signif-icant effect on the process of interflow except for the case on pounding time , and the interflow peak increases with rainfall intensity. Interflow lags with overland flow and the hydrological process display as a curve with only one peak.