Abstract: The Grain for Green is the most granted ecological restoration and reconstruction project in China. It has an important significance for eco-security assessment before and after the Grain for Green project to consolidate eco-environment achievement and to provide a basis for making regional environmental planning and sustainable development strategy. An eco-security evaluation index system about Grain for Green area was constructed using the press-station-response model, and the eco-security level before and after the Grain for Green project in Mudanjiang city was contrasted by the matter-element model. The results showed that: 1) The eco-security level in the urban and Suifenhe city declined, changed respectively from general security and security both to critical security. Well, the eco-security level in other counties had no change. 2) The correlation value varied obviously. The correlation value in Ning’an county dropt down, on the contrary, the correlation value in Dongning, Linkou, Hailin and Muling showed increasing trends and the eco-environment was improved significantly. In a word, the differentiation between indexes could be well revealed by the matter-element model. The results fit well to the real situation of the study area.