Abstract: By combining aerial remote sensing images with field investigations,two agricultural land use maps of the studied region in 1979 and 1999 were obtained.Comparison and analysis of the two maps showed changes in land use during that period of time.Through visits to farmers,causes of the changes were explored.The result showed that technology and input were the major contributors to higher yield of the farmland,and to increase the economic benefit of the farmland was the direct driving force of the changes in land use structure of upland fields.

Key words: change, land use, driving force, effect, Ziyang City, Sichuan Province