Land use results in a series of variations of soil physicalchemical property, furthermore influencing on karstification direction and intensity.Taking two spring basins at different elevation in Jinfo Mountain,Chongqing as an example,the authors analyzed the soil water and CO2 variation, soil water characteristics, solution rates in soil and their driving factors etc.The results showed that solution of tablets mainly occurs during the rainy season, with the mean weight loss in soil account for 65.5% and 71.9% of annual loss in Bitan and Shuifang spring respectively. It was also proved that soil CO2is an important driving factor for the ground carbonate rock denudation. Soil CO2and the residence time of the water are two major controlling factors which influence the weight loss in tablets placed in the soil. The intension of soil water transmission might be the decisive factor of solution rate in soil in dry season.