Abstract: Soil thickness is one of the most important factors restricting the ecological restoration in the region of Karst plateau. A case study was conducted in Wujinghe small watershed in Guizhou Province, China. The aim of this study was to characterize the spatial variability regulation and distribution pattern in soil thickness in Karst plateau. The soil thickness of three typical landuse types was measured in October, 2010 and analyzed by using traditional statistics and geostatistics methods. The results show that the degree of spatial variability in soil thickness in this study area was overall moderate, but strong in a few plots. All three landuse types had good semi-variance structure, and the spatial variability decreased with the decrease in slope position. The soil thickness was increased with the decrease in slope position. Relatively good spatial correlation and continuity of soil thickness exist between different sloping farmland. On the contrary, the degree of spatial variability in soil thickness was larger in both the barren hilly and Populus euramevicana plantation, and its spatial pattern came out as fragmentized distributions. Soil thickness can be well expressed by exponential model（R2≈0.8）in almost all plots, but fitted with spherical model and Gaussian model in a few plots. The research findings can provide deepen understanding of soil thickness, which will provide the foundation for Karst rocky desertification control project and rational utilization of land resources in Karst plateau region.