Vertical distribution of saturated hydraulic conductivity (K_s) has an important influence on soil hydrological processes. However, relatively speaking, few reports are available on this issue in karst areas with special geologic background. To study vertical distribution of soil saturated hydraulic conductivity (K_s) and its influencing factors in a small karst catchment, soil samples were collected from 23 soil profiles at 0～10, 10～20, 20～30, 30～50, 50～70 and 70～100 cm soil layers for measurement of K_s, rock fragment content (RC), bulk density (BD), capillary porosity (CP), non-capillary porosity (NCP) and soil organic carbon (SOC). Besides, environmental factors including slop position (SP), slope gradient (SG), slope aspect (SA), bare rock (BR) and land use type (LU) were investigated at each soil profile site, and all the data obtained were analyzed with the partial correlation analysis and canonical correspondence analysis (CCA) methods. Results show that K_sgenerally decreased with increasing soil depth and the variation could be fitted with a logarithmic function (R²=0.848). The variation of K_s in the soil layers within 20～100 cm was low in amplitude and approximate to each other, which indicates that K_s in the 20~30 cm soil layer could be used to represent K_s in the underlying horizons in building hydrological models. Among the soil properties, RC displayed the highest correlation coefficient (0.484) with K_s. In terms of influences of the environmental factors on vertical distribution of K_s, a decreasing order of SP > SG > SA > LU > BR was found. It is, hence quite obvious that RC is the most important soil property and SP the dominant environmental factor that influences vertical distribution ofK_s. The findings help understand the laws and major influencing factors of rainfall infiltration and also provide some scientific basis for vegetation restoration in small karst catchments and for building of hydrological models, as well.