The karst areas of Southwest China had been considered as one of four ecotones in China. To understand the impacts of the succession of vegetation on soil nutrient pool and the heterogeneity in the karst ecosystems, quadram sampling of topsoil was done and pools (total and available contents) and the spatial distribution were analysed under three different vegetation types (forest, shrubs and grassland) in karst mountainous area from central Guizhou province,China. The results showed that, both total and vailable pool of OC, N and P was highest under forest and decreased under shrub and grasslands, with the more prominent descending trend for available pools. However, highest satial heterogeneity of nutrient pools was found under schrub and associated with soil P. This indicated changes both in total pool and in spatial distribution with vegetation degrdation in the karst area. Nutrient availability was shown in prompt response to vegetation degradation. Changs in littering and the associated soil biochemical transfromation may occur under vegetation degradation which, in turn, may result in reduction of nutrient pool and increase in spatial variability. These changes in soil nutrient status may ultimastely impact on ecosystem cycling of life elements and the productivity in the long run.