The determination of agriculture land function and its dynamic variation in Zhifanggou watershed of loess hilly region were conducted with single change rate and dynamic land use comprehensive index method based on field investigated data(1938)2008).Results showed that the agriculture land functions evolved the following process: survival and ecological income and employment ecological and income during the evoluation of agriculture eco-economic system.The agriculture land use also experienced two stages:forest land converting to farmland farmland converting to garden land and forest land.The evolution trend was driven by the interact ion of populations,farmer requirements,agriculture benefit and government macro policies.