In this paper, we discuss the application status of Audio magnetotelluric method (AMT) in Nanling Yudu Gan county ore concentrated area Yinkeng demonstration plot to survey deep mineral resources. The purpose of carrying out AMT exploration work in this area is know of the strata distribution, distribution of rock mass and structure characteristic shallower than 3 km, which provide the basic geological information for deep exploration. The data of 5 AMT profiles is measured by vector observation scheme. After the da〖JP2〗ta pretreatment and inversion, we get the profile of resistivity changing with depth. Analysis of the result of the specimen resistivity test shows that resistivity difference exists between sedimentary rock, metamorphic rock and rock mass. The corresponding relation between formations and electric property is built based on the resistivity difference. Through comparison and analysis of the AMT geoelectric profiles, we obtain the space distribution feature〖JP〗 of Jiangbei rock mass and Changtan rock mass. The lower part of then has no roots. Meanwhile, we find a concealed rock mass named Liumukeng rock mass and infer the distribution of the sedimentary strata and metamorphic strata shallower than 3 km. This study shows that AMT method can provide useful geological information for “the second prospecting space”.