Based on the electromagnetic model of ferromagnetic/non-ferromagnetic/ferromagnetic layered films proposed in references 17 and 18 the enhanced giant magneto-impedance (GMI) effects and the GMI ratio dependence on the thickness of the constituent thin films are analyzed numerically in detail.It is showsn that larger difference of resistivity between the ferromagnetic and non-ferromagnetic layers as well as an optimum thickness of the layered thin films are beneficial to the improvement of the GMI effects.