Abstract: We investigated soil organic matter (SOM) content, grain yield of maize and sustainability yield index (SYI) and their relationship in Fuxin and Lingyuan sites of Liaoning province. The treatments included no fertilizer control(CK), nitrogen fertilizer(N), N and phosphorus fertilizers(NP), manure(M), manure and N fertilizer(MN), and manure combined with N and P fertilizers(MNP). Results indicated that SOM content was significantly increased by 5.2 g·kg^-1~11.1 g·kg^-1 under the organic treatments (M, MN, MNP), compared with the other inorganic treatments (CK, N, NP). The highest maize yield (6 757 kg·hm ^-2 for Fuxin site and 10 467 kg·hm^-2 for Lingyuan site) was observed under the MNP treatment and the lowest one was observed under the CK treatment at the both sites. SYI values were 0.50 and 0.54 under the MN and MNP treatments respectively, both significantly higher than the other treatments. This indicated that organic manure application can enhance sustainability of maize yield. SYI was significantly correlated with SOM content (R²=0.74) under manure application, indicating that the increase in SYI induced by manure application was attributed to the SOM increase.