The principle and method of analytic hierarchy process(AHP)were applied to assess the sustainable development factors of converting farmland into forest/grassland in North Shaanxi Province.Twenty indexes are weighted,in which the first class indicator includes four factors,that is,ecology system,economic system,population system,and policy management system.Results showed that the factor of eco-efficiency was the greatest weight factor,being about 50% and the second one was economic development indicator,being about 30%.They matched the reality exactly.All of them lay the basis and foundation for the post-period plan in the region.