Abstract: In this study, the effects of long-term different fertilizations on black soil carbon and labile organic matter were studied in a background of special natural conditions of the northeast black soil region, in order to find out the ideal proportions between organic manure and chemical fertilizer and provide reference for soil improvement in the black soil region. The results showed that each fertilizer treatment played positive role in the accumulation of total carbon, organic carbon and labile organic matter (LOM) in black soil. Compared with chemical fertilizer treatment (NPK), the treatment of combined application of organic manure and chemical fertilizer obtained the best result. In the combined application treatment, there was no obvious relationship between organic manure application amount and the contents of total carbon, organic carbon and LOM.