Black soil plays a crucial role in food security and sustainable development of the ecology in China. In the past 50 years the content of soil organic matter (SOM) in the black soil in Northeast of China has been decreasing, thus posing a critical problem of how to maintain its productivity, which has become a hot spot in agricultural science. Based on the long-term stationary fertilization field experiment, variation of soil fertility of and fertilizer efficiency in black soil as affected by long-term fertilization was explored and effects of long-term fertilization on content of soil labile organic matter and carbon pool management index were evaluated. This experiment was laid out in 1990 and designed to have 12 treatments, i.e. CK₀, CK, N, NP, NK, PK, NPK, SNPK, MNPK, MNPKW₂, 1.5MNPK and 2MNPK. All the treatments have the same cropping pattern, mono-cropping of maize, except for Treatment MNPKW₂, which follows a maize-maize-soybean rotation system. In 2013, soil samples were collected from the topsoil (0～20cm) layer for analysis of labile soil organic matter. Contents of three fractions of labile organic matter, namely highly labile organic matter (H-LOM), moderately-labile organic matter (M-LOM) and low-labile organic matter (L-LOM) were determined using 33 mmol L^-1, 167 mmol L^-1 and 333 mmol L^-1KMnO₄, respectively. Results show that contents of soil organic matter in all the fertilized treatments increased to a varying extent. Compared with the initial content (23.3 g kg^-1) of soil organic matter (SOM), it increased by 35.6% in Treatment CK₀ , by 10~15% in Treatments N, NP, NK, PK and NPK, the least in increment, by 20% in Treatment SPNK (NPK plus straw incorporation), and by 66.38 %~92.13 % in Treatments MNPK, MNPKW₂, 1.5MNPK and 2MNPK, the most significant increment. The content of H-LOM, M-LOM and L-LOM were 0.94~4.18 g kg^-1, 0.39~5.10 g kg^-1 and 2.45~11.36 g kg^-1, respectively, accounting for 4%~10%, 1.59%~10.28% and 8.71%~27.45% of the total organic matter, respectively. The content of H-LOM, M-LOM and L-LOM in organic fertilizers treatments, were higher than their corresponding ones in the other treatments, and the more the organic manure applied, the higher, the contents of SOM. The contents of the three fractions of SOM were low in mere chemical fertilizers treatments and Treatment CK, and did not vary much between those treatments. However, Treatment CK0 and Treatment MNPK did not differ much in content of H-LOM, M-LOM and L-LOM, suggesting that fallow had a significant SOM increasing effect. Carbon pool management index (CPMI) is an important parameter to characterize status of soil nutrients. Treatment CK0 did not have much improvement in CPMI of LOM), whereas Treatment 2MNPK exceeded 200, the highest among all the treatments. For M-LOM, CPMI was 22.08 in Treatment CK, lower than any other treatments. Compared with Treatment CK, Treatments N, NK, NP, and PK did not improve much in CPMI, but Treatments NPK, SNPK, MNPK, MNPKW₂, 1.5MNPK, 2MNPK and CK0 did quite significantly, with the highest CPMI being 176.64 in Treatment 2MNPK. On the whole, in terms of CPMI, the treatments followed an order of organic fertilizers > fallow land > straw incorporation> mere chemical fertilizers. For organic treatments, the more the organic manure applied, the higher the CPMI. CPMI was higher in Treatment MNPKW₂ than in Treatment MNPK, suggesting that the maize- maize- soybean rotation system is a good way to improve CPMI.