Based on landuse change data obtained from TM images in 1986 and 2003 and the relative ecological values of corresponding landuse types,we evaluated ecological effects of returning farmland to forest or grass land in Wuqi County. Results show that landuse types in the county were in a significant change during 1986-2003.The total area of woodland and grassland has increased greatly while the area of farmland and unused land has significantly reduced.There was 63.55% of farmland transferred into woodland and grassland.Ecological environment has been significantly improved and overall environmental quality has been remarkably improved.Ecological contribution rate of returning farmland to forest is 40.96%. Projects of returning farmland to forest land in Wuqi County have achieved success and brought wonderful ecological effects.