The grain for green project,as a major measure for vegetation construction,plays a very important role in accelerating eco-environment restoration on the Loess Plateau.Based on the arable land pressure index,the effects of the grain for green project on food security were evaluated by taking the Yan'an demonstration area of soil conservation and eco-environmental construction as a study object.Results showed that the grain for green project has achieved the purpose of“food for ecology”.Arable land pressure decreased by 75.5%in northern forest-meadow region and remained balance basically in southern forest region to a large extent.However,arable land pressur rebounded and reclamation occurred sometimes due to the ending of the project and the change of food subsidy policy after 2003.Arable land pressure from 2004to 2009was 1.8～4.8and 1.1～1.7times of that of 2003in the north and the south,respectively.Among them,arable land pressure for the south was greater than 1after 2007,which should be paid more attention.Longevity and stability of food subsidy should be ensured in future,so as to insure the sustainable development of ecological restoration.