[ Objective ] To explore the influence mechanism of soil water erosion on the patch distribution pattern of Stipa krylovii in Xilamuren grassland, and to provide theoretical basis for soil erosion control in this area. [ Methods ] Three distribution patterns ( aggregation distribution pattern, uniform distribution pattern and random distribution pattern ) and two controls ( non-grazing and bare slope ) were set up by field investigation and variance mean ratio method. The indoor simulated rainfall experiments with rainfall intensity of 30, 60, 90 and 120 mm/h were conducted to quantify the sediment production and abortion processes on slopes with different distribution patterns. [ Result ] ① The distribution pattern of heavy grazing and no grazing was aggregation distribution pattern, the distribution pattern of moderate grazing was uniform distribution pattern, and the distribution pattern of light grazing was random distribution pattern. ②At 30mm/h rain intensity, no runoff was produced, and at 60mm/h rain intensity, the runoff yield showed bare slope > aggregation distribution pattern> random distribution pattern> uniform distribution pattern> no grazing.；the rainfall intensity at 90mm/h showed bare slope > aggregate distribution pattern> uniform distribution pattern> random distribution pattern> no grazing. At 120mm/h, the rainfall intensity showed bare slope > aggregation distribution pattern> no grazing > uniform distribution pattern> random distribution pattern.③At 30mm/h, there was no sediment production, and at 60mm/h, the sediment production rate showed bare slope > uniform distribution pattern> no grazing > ra-ndom distribution pattern> aggregation distribution pattern.The rainfall intensity at 90mm/h showed bare slope > aggregate distribution pattern> uniform distri-bution pattern> random distribution pattern> no grazing. At 120mm/h, the rainf-all intensity showed bare slope > no grazing > aggregate distribution pattern> uniform distribution pattern> random distribution pattern.④The sediment reduct-ion benefit of random distribution of 120mm/h rain intensity can be reduced b-y 88.76%, and the non-grazing flow reduction benefit of 90mm/h rain intensity can be reduced by 45.78%.[ Conclusion ] Grazing promoted the patching ph-enomenon of Stipa Krylovii, and soil water erosion intensified the formation of bare patches, which led to different distribution patterns of Stipa Krylovii patc-hes.