© 2017, Electromagnetics Academy. All rights reserved. In this paper, an effective numerical method based on a new surface impedance model is applied to the accurate calculation of the radar cross section of lossy conducting targets. The problem of determining the scattered electromagnetic fields from rectangular lossy conducting strips is presented and treated in detail. This problem is modeled by the method of moments to resolve integral equations of the first kind of surface current density with an accurate choice of basis and test functions. The illustrative computation results of complex surface impedance, surface current density and radar cross section are given for several cases. The accuracy of the method presented in this paper is verified by comparison with other methods, including the general-purpose full-wave simulators HFSS and CST.