A new numerical method, iterative loop-EMF method, for quantifying the induced EM field in a finite, heterogeneous, non-magnetic body irradiated by an incident EM field has been developed. In this method, the body is modeled by an impedance network and Faraday's law is used to relate the induced loop electric field (or current) to the induced magnetic field. In the mean time, a coupled tensor field integral equation is used to iterate the induced electric and magnetic fields. This method can improve numerical accuracy of the existing tensor electric field integral equation method. The theoretical analysis and numerical examples are both presented. Good agreement is obtained by the comparison with the previous published results.