Abstract: Abstract: Surface soil moisture content (SMC) has a crucial effect on rainfall infiltration, runoff generation, evaporation and other soil hydrological processes. However, knowledge of SMC distribution was limited in Karst areas with discontinuous thin soils containing high content of rock fragments. In this paper, based on 80 m×80 m sampling grid, 162 undisturbed and disturbed soils was sampled to measure SMC and other soil properties, including bulk density (BD), capillary capacity (CP), non-capillary capacity (NCP), soil organic carbon (SOC), and rock fragment content (RC). Environmental factors including topographical position (upper-slope, middle-slope, lower-slope and depression), land use type (forestland, shrubland, shrub-grassland and farmland), slope gradient (SG), slope aspect (SA) and bare rock (BR) were investigated around the sampling points. Spatial variability of SMC and its influencing factors were analyzed by both geostatistical and classical analysis methods. The results showed that the mean value of SMC was 34.43%. The SMC had a moderate variation with the coefficient of variation of 0.33. The geostatistical results showed that the semivariance of SMC was best fitted by exponential model with a higher determination coefficient of 0.910. The range was 381.00 m and the nugget/sill value was 0.382, indicating a moderate spatial correlation of SMC. When the lag distance was smaller than 200 m, the variation in 120° direction was higher than that of 30° direction. However, when the lag distance was exceeded 200 m, no anisotropy was found in 120° and 30° directions with the anisotropy ratio fluctuated around 1. The Kriging map showed that SMC generally decreased with the increasing altitude. Most of the slope had a lower SMC value less than 35%. The highest SMC value always appeared in the east of the depression which was higher than 50%. The Pearson correlation analysis showed that CP had a significant (p < 0.01) positive correlation with SMC but RC and BD had a significant negative correlation with SMC. NCP had a significantly negatives effect on SMC with the significant value of 0.022. However, SOC only significantly affected SMC at 0.10 level. This suggested that all the soil properties had important influence on SMC. However, for the topographical factors, only SG had a significant influence on SMC with the correlation coefficient of -0.435 (p < 0.001). The analysis of covariance showed that the interpretation of RC, CP, and NCP was significant (p < 0.05). However, topographical location, land use type and their interaction effect were not significant. This indicated that the soil properties were the direct influencing factors. Topographical locations and land use types influenced SMC mainly by changing the soil properties. The explained variation of topographical location was higher than that of land use type. This indicated that topographical locations had more important effect on SMC than land use types. These results will help to understand the spatial distribution of SMC and to distinguish the main influential factors of SMC in Karst catchment. They also provide knowledge on ecological conservation and restoration in Karst regions.