Carbon distribution and storage estimation are one of the key issues in the researches of carbon cycling and global climate change impact. Data of the second soil survey in Hubei Province were used to investigate the vertical variations of the concentration, density, and bulk density of organic carbon in soil layer in-depth down to 1 meter. And the organic carbon storages at different depth (stratified into 5 layers) and overall layer (1 meter in depth) for the total 13 soil types in Hubei Province were also estimated. The results showed that for all soil types, with increasing soil depth, the organic carbon concentrations and organic carbon density decrease, and their bulk densities increase. Total organic carbon storage of the Province is 1.1 Pg, in which the storage in surface soil is 0.385 Pg, accounting for 35% of the total storage. For the all studied 13 soil types, the maximum and minimum organic carbon densities are mountain meadow soil and purple soil, their organic carbon density are respectively 32.46 and 3.41 kg/m~2. The average carbon density is 12.87 kg/m~2, higher than that of the national level (10.53 kg/m~2), implying a higher coverage of vegetation, and denser accumulation of organic matter in the Province, which is beneficial to ecological system and agricultural production.