Abstract: To ensure the food security, the Chinese government had reclaimed the wetland in Sanjiang Plain(northeastern Heilongjiang Province) many times and this degenerated the soil and deteriorated the ecosystem of the region. Based on evaluating the value of ecology service of wetland and farmland ecosystems and taking into account of the food security and ecology security, the paper researched the tradeoff of conflict between wetland protection and farmland reclamation and put forward some suggestions: 1) the farmland should be firmly converted to wetland in the core area of wetland protection region; 2) the wetland fragments should be pooled together in order to bring their effects into full play; 3) the ecologically used water should, if possible, be taken into consideration from the aspect of watershed; 4) the scale of farmland reclamation should be strictly controlled.