The characterization of the spatial variability, distribution and influencing factor of soil moisture is of paramount importance in many ecological processes and operational applications, especially in the karst area of China. In this study, soil moisture was measured with a portable T DR for a layer depth of 0-16 cm in a karst depression area of southwest China during the dry and rainy seasons of 2005, and the spatial variability, distribution and influencing factors of soil moisture content were investigated by using the geo-statistics and GIS method. The results indicated that the surface soil moisture content was influenced by the antecedent rainfall (the rainfall accumulation 10 days before the sampling time) and it was more sensitive to the antecedent rainfall in dry season than that in rainy season. The mean soil moisture content varied from 21.67% to 28.79% during the dry and rainy seasons. The soil moisture content showed middle variability, and the CV values decreased with the increasing mean soil moisture content either in dry or rainy season. The parameters of semi-variogram theoretical models of soil moisture content indicated that the spatial variability and its dominant influencing factor of soil moisture content both changed with the dry and rainy season. Similar results were also obtained from the pattern of soil moisture content, which generated by the ordinary kriging interpolation. The soil moisture content, its distribution and variability were always different at different sampling time and region. But, a similar pattern of the soil moisture content was observed on the whole in the two seasons, with drier zones always becoming drier and vice versa. Also, the distribution of soil moisture content showed mosaic pattern in dry season, compared with the strip or band pattern in rainy season, which were caused by the combined influence of environmental factors and human activities. What's more, the variability of soil moisture content by CV values decreased with the increasing mean soil moisture content due to the antecedent rainfall either in dry or rainy season. And the soil moisture content was different in different land use types. The abandoned field and orchard field always had relatively higher soil moisture content either in dry or rainy season, followed by the rehabilitated field and gazing field, and the cultivated field had relative lower soil moisture content. Furthermore, a significant positive correlation was found between the soil moisture content and the soil organic carbon. Altitude and bare-rock ratio were also important factors influencing the soil moisture content in the depression area. Therefore, rational strategies of soil water resource usage and management should be made according to the different spatial distributions and influencing factors of soil moisture content in dry and rainy season in the depression area of karst region.