Abstract: Based on interpretation of Landsat TM images obtained in 1984,1995,2000 and 2003 and large volumes of historical socio-economic data of the study area,quantitative analysis was carried out of the relationship of some socio-economic factors with expansion of non-agricultural land.Results indicate that the driving factors manifested temporal variation between different stages in the past 20 years,1984-1995 and 1995-2003;the local booming economy(represented by GDP) is the dominant driving force,the impact of economic radiation of Shanghai on Suzhou and growth of the population are the other two main driving forces.