Due to the increase of atmospheric gas concentration in greenhouse,climate warming caused great inconvenience to people's production and living. Therefore,soil carbon pool [soil organic carbon (SOC) and soil inorganic carbon (SIC)]has attracted much attention. Straw returning farmlands and abandoned farmland changed the input carbon,which affected the SIC and SOC conversion processes and soil carbon pool. SIC has a long retention time,and SOC plays an important role in the formation of soil aggregates and the adsorption of mineral nutrients for plants. With rural population reduction, straw returning farmland,abandoned land and woodland are very common. There is lack of research on the effects of land use change on different soil carbons. The results showed that SOC is the most sensitive to the soil depth of the farmland, followed by abandoned land,the lowest sensitive forest land. The density of SOC in the topsoil of forest land was the largest,followed by farmland,and the smallest was abandoned. The SOC carbon density in woodland was 2.26 times of that in abandoned land. SOC carbon density in farmland was 1.37 times of that in abandoned land in 0-140 cm soil. The abandonment farmland SIC density was the biggest,followed by farmland,with the lowest SIC carbon density in forestlands. In the 0-140 cm soil layer,the SIC densities were 12.37,11.68 and 9.77 kg ·m~(-2),respectively. SIC carbon density in abandoned fields was 1.27 times that of woodland. With the development of rural areas in China,a new way of land use management has emerged,estimating the impact of land use on soil carbon needs to consider SOC and SIC.