Rational Function Model (RFM) is one of the universal imaging models with characteristic of sensor independency.The geopositioning solution based on Rational Polynomial Coefficients (RPC) is studied using QuickBird separateorbit stereo image pair in Shanghai district,China.The principle of RFMbased stereo positioning method is first introduced,and the positioning errors are then analyzed.Based on this,enhancing models are further presented for the improvement of geopositioning accuracy.The experimental results show that the affine model works best in the test area.The accuracy can reach to 0.6~0.8 m in planimetry and about 1.0 m in elevation based on the affine model by using 5~6 well distributed control points.