Global climate change and its impacts on the human face is one of the major environmental problems. A great increase in atmospheric CO_2 concentration brings more and more serious environmental problems to human life. Soil organic carbon is an important part of the terrestrial ecosystem carbon pool. While its slight change has a direct impact on the greenhouse gas concentrations in the atmosphere. In this paper,in terms of the carbon data of multi purpose regional geochemical survey in 2003 ~ 2010 and the second soil survey of Shandong Province in the 1980s,it is shown that soil organic carbon at the depth of 1. 0m accounts for 3. 28% of SOCP, which showscarbon sink; carbon density is highest in paddy soil,and the second highest in Shajiang black soil,then lowest in coastal saline soil. Soil carbon sequestration potential is 1. 02 * 10~9 t in the 0 ~ 1. 0 m - depth soil in the study area,which means it can reduce the concentrations of atmospheric CO_2 by 0. 081%. Through the correlation analysis it is indicated that using organic fertilizer and N,P,K,Zn fertilizers,mineral fertilizer in the soil can improve soil organic carbon content and soil carbon sequestration. Meanwhile,the reason that makes soil carbon sequestration be destroyed is too much Cl. This study provides the scientific basis for remission of atmospheric CO_2 concentration which leads to the increase of environmental pressure and improving Chinas soil ecosystem carbon sequestration potential.