Abstract: The mechanism of degraded Karst vegetation restoration was a popular research topic in soil science and ecology for the last decade. Soil microbial biomass C was recommended as one of major characteristics of soil quality in the processes of degraded Karst vegetation restoration. The test soil was taken from the Karst plateau Ecological Synthesis Control Area in Huajiang of Guizhou. The changes of soil microbial biomass C with different microhabitats, different soil layer and Rhizospheric, Non-rhizospherie were studied during the process of degraded karst vegetation restoration. The results showed that soil microbial biomass C had obvious difference. With degraded Karst vegetation restoration, the soil microbial biomass C were ascending obviously, i. e. arboreal community stage>shrubby community stage>herbaceous community stage>bare land stage. It indicated that the soil quality has been restored gradually. The microhabitat characteristic of soil microbial biomass C was ascending as stone gully>soil surface>stone-groove in the bare land stage and herbaceous community stage. The shrubby community stage and arboreal stage were stone-groove>soil surface>stone gully. The characteristic of vertical distribution in the soil profile decreased with the increase of the soil depth. It presented as A>B. The soil microbial biomass C in rhizosphere was greater than that in non-rhizosphere.