Abstract:The paper presented a new MT inversion method for 1-D layered medium-"forward modified method".Through comparison of real apparent resistivity curve with theoretic apparent resistivity curve by 1-D forward computation,the method modified in turn the resistivity and the thickness for each conducting layer.Because the method can divide underground medium into as many conducting layers as points of surveying period,it can vertically reflect the resolution of conducting layer in maximum which can reflect in surveying data.In a range of intrinsic equivalence of MT,"forward modified method"can correctly restore resistivity and thickness for each conducting layer.The model test showed that the method is more accurate,stably convergent and practical method.