Abstract:A new indirect method for determination of soil carbonate was proposed and established by comparing with neutralization titration method in measuring the recovery of added CaCO3. First, soil total carbon content (TC) was measured with the elemental analyzer (Vario MAX C/N), and then soil organic carbon content (SOC) with the potassium dichromate oxygenation method. And finally, based on difference between TC and SOC, soil carbonate content (SIC) was estimated. Using the indirect method, total carbonate in calcareous soil and lacustrine sediment soil from Guangxi and Hunan in subtropical China was determinated. Results indicated that only some of the calcareous soil samples contain carbonates. The proportion of soil samples which contain carbonate in woodland, upland, and paddy soil was 50.0%, 43.7% and 2.1%, respectively. The carbonate contents of these woodland, upland and paddy soil were 134, 15.7 and 37.1 g/kg, respectively. All of the lacustrine sediment soil samples contained carbonate with average carbonate contents of 73.3, 46.6 and 37.3 g/kg, respectively in upland cultivated for three to five years, upland cultivated for a long time and paddy soil. The impact of land use and soil parent on the soil carbonates content is significant.