Abstract: Based on the organic carbon and total carbon test results of the black land surface matrix survey in Qiqihar area of the Songnen Plain, the soil organic carbon and total carbon storage, density and spatial distribution in plain areas of Yi'an, Fuyu, Baiquan, Keshan and Kedong counties in Qiqihaer area of Heilongjiang Province are studied. The results of research and analysis show that the carbon storage of five counties in Qiqihar City, Heilongjiang Province is about 82.45 Mt, and the organic carbon storage is 68.12 Mt, which is at a high level. Geostatistical analysis shows that the organic carbon storage in the region has a certain spatial autocorrelation, and the organic carbon density shows a decreasing trend from northeast to southwest. The main controlling factor is water erosion of Nenjiang River, followed by changes in soil type and land use type. The carbon sequestration potential of organic carbon in the research area is 23.17 Mt, and the total carbon sequestration potential is 27.10Mt, with significant room for growth.