Abstract: Under the control of subtropical humid monsoon climate, karstification is very strong in the karst area of southern China. At the same time, a lot of researches indicate that the carbon sink formed by karstification in southern China may be an important part of the global missing carbon sink. At present, there are many research methods to estimate the intensity of karst carbon sink. The carbonate rock tablet test is one of the main traditional research methods to estimate the karst carbon flux. The main principle of this method is based on the chemical reaction of water-CO₂-carbonate rock. The specific operation is to bury the carbonate rock test piece with the same size under the soil, then take them out and weigh them after a certain time, use the dissolution amount of rock tablets to calculate the dissolution rate and karst carbon flux in study area. Finally, the regional karst carbon sink can be estimated according to"point by area". In the study of estimating karst carbon sink in China, previous scientists used pure limestone from Rongxian formation of Devonian System in Guilin. However, the geological background of different regions is quite different, and the composition and structure of bedrock are different, so that the estimation results of standard carbonate rock tablets (pure limestone) may be also different from the actual dissolution amount of local bedrock tablets, resulting in great uncertainty in the estimation of karst carbon sink in the region. Based on this, in this study, we chose Puding county, Guizhou Province as the study area. The main bedrock types (limestone and dolomite) of this place are made into standard size rock tablets, and buried them in the typical land use types (secondary forest, shrub, grassland, dry land and paddy field) in the study area. After monitoring for four hydrological years, the dissolution rate and karst carbon flux were calculated, then compared them with the previous research results using the standard carbonate rock tablet (pure limestone) in the same study area, and the following results are obtained; (1) Under the same climatic conditions and soil environmental conditions, lithology has a significant impact on the dissolution rate of carbonate rock tablets, and the dissolution rate has a positive correlation with CaO content in the rock tablets and a negative correlation with MgO content in the rock tablets; (2) The difference of dissolution rate between limestone and dolomite is controlled by land use types and soil depths. Without considering the influence of environmental factors, on the whole, the dissolution rate of limestone is 14% higher than that of dolomite; (3) The karst carbon sink intensity estimated by different lithology carbonate rock tablets varies greatly. The estimated result of standard limestone tablets is higher than that of local tablets in this study. Therefore, when using the carbonate rock tablet method to estimate the regional karst carbon flux, we should consider the lithology of the bedrock where the rock tablet is buried, or correct the estimation results based on the standard carbonate rock tablet, so as to accurately obtain the real karst carbon flux on the regional scale.