The land use change graph from 1982 to 2003 of Xiaojiang watershed in typical karst region was analyzed by GIS based on 2 times spatial data.The results showed: (1) the cultivated land increased was the most important changes

which was transformed from unused land. 610. 12 km2 land use had been changed

of which 268.5 km2 or 44. 01% of the total was changed into cultivated land during the past 20 years in Xiaojiang watershed.(2) The annual change rate of regional land use was 2. 95%

while the annual change rate of cultivated land

unused land and forest land were 10. 55%

4. 08% and 5. 95%

respectively.(3) The spatial pattern of land use in Xiao jiang watershed changed from composed of large and scatter patches mosaic to compose of middling and scatter patches mosaic

and the types of dominating patch have also been changed

which changed from unused land and forestland patch to cultivated land and forest land patch. (4) When the spatial pattern of land use in Xiaojiang watershed was analyzed quantitatively by introducing the diversity index

dominance index

homogeneity index and broken index

a clear picture of the interference degree caused by human activities can be made. As the increasing of disturbances from human

the diversity index

the homogeneity index and the broken index all increase

especially the broken index increased by 84.6%.(5) By analyzing of the change of the land use gravity center

the change of land use spat ial pat tern was very obvious during the past 20 years in Xiaojiang watershed.The land use gravity center has changed in different speed. Finally

analyzed quantitatively by introducing society and economy data

it was clarified that the rapid growth of population and the economic development for survival were the main driving forces of land use change in Xiaojiang watershed during the past 20 years. Furthermore

macro-policies such as ecological protection were also important human driving forces of land use change.