In this paper three electromagnetic scattering similitude laws for the model measurements of lossy target are presented. The Radar Cross Section（RCS） of the measured model can be transfered to the RCS of the full-size target （prototype） by using one of the similitude laws.The scope of application

similarity requirement

induced similarity ratio of RCS and experimentel results for the three similitude laws are also given. The experimental re-sults for the first similitude law shows that the agreement between measured result of the prototype and the result transfered through the modelling measurement is very good. The transfered error is about 1-2 dB. The exact solution of the conducting sphere coated with dielectric material is also used to verify the three laws. The second and the third laws can be uaed in the full band with transfer error less than 1 dB. The first law can only be used in optics region and there is large error in the Rayleigh and resonant region.