Field study was conducted in a corn cropping system in reclaimed minesoils of the aluminum mining wasteland in 2010 in Xiaoyi City, Shanxi Province in north of China. The purpose was to characterize the soil organic under different microbial fertilizers of biological activator, biological agents, and control treatment, i.e. without any microbial fertilizer in the maize (Yitian18) cropping system. The measurements included the organic carbon content and the values of δ13C of soil in the depths of 0 – 20 cm and 20 – 40 cm, and the values of δ13C in maize stem and grain. Results showed that deeper soil corresponded to reducing soil organic carbon but increasing δ13C values. Microbial fertilizers could significantly increase soil organic carbon content. Maize grain accumulated much more 13C than stem, as evidenced by the statistically significant difference, in spite that no significant correlation was found. Based on the results it is concluded that microbial fertilizers could improve the accumulation of soil organic carbon in aluminum mining wasteland.