Based on two Landsat MSS/TM remote sensing images from 1980 to 2007 and 150000 topographic map

a quantitative research on land cover spatial temporal changes pattern of different elevation and slope grades of Yuli County during 1980-2007 was conducted with remote sensing and geographic information system technologies.Results showed that (1)Cropland

wood-grassland

water body

built up land changed prominently during the past three decades

cropland was mainly converted from wood-grassland

water body was mainly transferred into wood-grassland;(2)Built-up land expanded in high elevation area;cropland and built-up land distributed consistently on each gradient

change direction of both land covers was identical

and expanded into the region of steeper slope;(3)Wood-grassland increased dramatically at locations below 3

but it showed a decline trend at position above 3;(4)Water body kept shrink across the whole region.It is feasible to predict the spatial distribution of land cover based on topographic data

remote sensing images and social economic data.