MSE(Minimum Mean Square Error) is widely used as the criteria in image coding algorithm for providing much detail and important information of small target.In order to remain more detail information,an algorithm was proposed for determining the significant coefficients and the lifting value.The final coding bit-plane can be estimated by the entropy estimation of the DWT coefficients,and also the significant coefficients can be defined and the lifting value can be determined.The difference between proposed algorithm and ROI(Region-of-Interest) is that the definition of significant coefficients and the lifting value can be obtained from the coding image and the given coding rate so that the algorithm can be regard as the generality of ROI coding algorithm,but more flexible.The experimental results show that the small targets in remote-sensing images can be saved validly,while the detail information in reconstructed image are lost a little.