Recently, a significant increase in soil organic carbon storage in the North China Plain has been reported as carbon sinks by a number of studies, while the corresponding relationship of soil organic carbon with climate change remains uncertain. Based on the previous studies, a total of 20 029 surface soil samples of national multipurpose regional geochemical survey and the data of annual average temperature and annual precipitation of the related weather stations were used to analyze the relationships between topsoil organic carbon density and annual average temperature and annual precipitation by applying the multiple linear regression in Hebei Plains. The different zones characterised by the temperature and precipitation were also taken into consideration in the present study. The results show that the changes of annual average temperature and annual precipitation are 0.29 ℃ per 10 years and -25.99 mm per 10 years, respectively. The average soil organic carbon density in the study area is (2.19 0.78) kg/m~2, with a range of 0.18-18.72 kg/m~2, decreasing from West to East spatially. The change of soil organic carbon storage is 39.17 Mt. According to the linear regression modeling with climatic factors as predictors, the soil organic carbon density in the study area is mainly controlled by the change of temperature, and is restricted by precipitation as well. However, the soil organic carbon and its change depend on not only the annual average temperature and annual precipitation, but also other factors, such as agricultural activities, which influence the soil organic carbon in the study area. Our results indicate that the influence of climatic factors on soil organic carbon at large scales can be effectively illustrated by taking full account of the annual average temperature and annual precipitation zones.