MT tensor descomposition method and its improvements are introduced,and more credible real regional structural strike be determined by decomposing the actually measured MT data using the iproved method.Combining the decomposition results,the response function such as apparent resistivite,phase,strike,skew et al.and dimensional weight parameter to make a comprehensive analysis,the more detailed information for the demensional parameter of structure can be obtained.The study of the actually measured MT data in Lanzhou area shows:in the area the regional conductivity structure is mainely two dimensional,and the strike is approximately in north-south or in west-east.