Based on the historical data of cultivated land and economic development in 1990 - 2006, the paper analyzed the spatiotemporal change characteristics of cultivated land in Changsha City. The main factors to driving forces in cultivated land change were then analyzed by the principal component analysis and multiple regression analysis. Results showed that (1) the cultivated land in Changsha City presented a downward trend in 1990 —2003 and a slight rising trend in 2003 - 2006. The annual decline percentage between 1990 and 2006 was about0. 26 %. (2) Regional difference between regions was obvious. (3) The principal component analysis indicated that economic factor and agricultural factor could be summed up as the two main factors to reducing cultivated land in Changsha City and the economic factor was the key one. (4) Multiple regression analysis also indicated that the economic factor was the most important influence factor to the change of cultivated land in Changsha City.