[Objective] With the development of urbanization, a large number of natural lands or agricultural lands are changed into urban land, which bring about dramatic changes in soil carbon stocks. It has an important significance for understanding of urban soil carbon pools and the response to global change to research the soil carbon storage in city area.[Methods] The inner Xi'an beltway area was selected as research range, where the soil carbon pool was researched. Total 230 surface soil samples under different land uses/functions were collected, and soil organic carbon of each sample was analyzed by Vario ELⅢ elementer.[Results] The soil organic carbon ranged 0.88~27.18 g/kg with a mean of 5.59 g/kg; and the organic carbon density was 0.22~7.11 kg/m² with a mean of 1.41 kg/m². The total carbon storage was 6.32×10⁵ t in the city area of inner Xi'an beltway, the average per square kilometer was 1.37×10³ t. The scenic recreation and traffic area were the regions with high soil organic carbon content, and the industrial zone was relatively lower. A north-south strip of high soil organic carbon with city center as concentrated core was recognized.[Conclusion] The soil organic carbon distribution pattern of Xi'an City maybe relate to some indices prior to urbanization, as soil use, green management, garbage of food and fuel residues and waste water into the soil. The organic carbon content near traffic road was affected by black carbon settlement from vehicle exhaust emissions. The overall topsoil organic carbon content of Xi'an urban was significantly lower than that of other domestic cities.