On the base of first order dynamics model, combining with a laboratory soil incubation experiment, decomposition characteristics of soil organic carbon (SOC) in China typical regions were analyzed. The results showed that there were two decomposition stages of SOC which with a faster decomposition at early stage and a slower one at the later stage. After two months of its equilibrium time, the amount of daily mean decomposition of SOC became very smaller. In the east region, decomposition rates of four zonal soils organic carbon increased with latitude. In these six areas, the total SOC pool contents ranged from 2.31g/kg to 81.93 g/kg; the active carbon pool content ranged from 0.09 g/kg to1.04 g/kg, slow carbon pool content ranged from 0.90 g/kg to 33.39 g/kg and the passive carbon pool content ranged from 0.92 g/kg to 47.85 g/kg.