【Objective】After receiving precipitation, exposed rock surface in a rocky desertification area exposed to bedrock is easy to form rock surface flow, which carries organic and inorganic substances on the rock surface to the surrounding soil. This has a significant impact on the change of soil nutrients at the rock-soil interface. 【Method】 This study was designed to investigate the effect of rock surface flow on the leaching and input of nitrogen and phosphorus in the soil at the rock-soil interface. Three plots: fallow land (one-year rock surface flow), abandoned irrigated grassland (five-year rock surface flow), and sloping farmland (no/little rock surface flow) with obvious bedrock exposure, were chosen. We chose three special shapes of the rock surface, namely convex, straight, and concave, at different horizontal distances from the rock surface and soil layer to study the variation characteristics of total nitrogen and total phosphorus in the soil at rock-soil interfaces and non-rock-soil interfaces. 【Result】 The results indicated that rock surface flow contributed either to the input or leaching of nitrogen and phosphorus in the 0-10 cm surface of the rock-soil interface soil. However, it had a minimal effect on nitrogen and phosphorus in the 10-20 cm deep rock-soil interface soil. The intensity of the leaching and input of nitrogen and phosphorus in the surface soil of the rock-soil interface formed by different rock surface shapes followed concave > straight > convex. In the 1-year fallow land, under the action of rock surface flow, the influence of rock surface flow formed by concave rock surface on soil nitrogen at the rock-soil interface was mainly manifested as leaching, while flat and convex rock surfaces exhibited input effects. Also, the effects of rock surface flow with different shapes on soil phosphorus at the rock-soil interface showed leaching. For the 5-year rock surface flow, the result depicted mainly an input phenomenon. 【Conclusion】These results can provide a scientific basis for further understanding the influence of exposed rock on soil characteristics of the karst ecosystem.