Surface roughness is one of the important parameters affecting surface erosion, and it is also one of the hot issues in soil erosion research. It is of great significance to study the spatial heterogeneity of surface roughness in Feldspathic Sandstone Region during natural rainfall to explore the response law of soil erosion. In this paper, the spatial heterogeneity of surface roughness of bare Feldspathic Sandstone Region was studied by geostatistics and ArcGIS spatial analysis. The results showed that:the surface roughness showed a moderate variability during one rainfall event. The surface roughness had a strong spatial autocorrelation during one rainfall event. According to the analysis of spatial distribution characteristics, the increase or decrease of surface roughness was obvious in the downhill of the slope, indicating that the changes of the slope were that the top of the slope was scoured, and the bottom of the slope was filled. The contents of sand and silt particles were decreased, but clay increased. The surface roughness changed more obviously at the bottom slope. Therefore, the surface roughness changed with the changes of soil clay particles. Before and after rainfall, soil clay contents and surface roughness showed a positive correlation, which was more strong after rain. The relationship between silt and surface roughness was not significant, and sand and surface roughness showed a negative correlation.