This paper presents the results of magnetotelluric investigation in Tarim Basin. We complete the survey at 701 stations and perform data processing and 3D inversion, obtaining 3D lithospheric electrical resistivity model of the Tarim terrane, which reflects lithospheric structures from viewpoint of electrical properties. After interpretation of the results, we determine that the electrical thickness of the asthenosphere in the terrane is 138km, sedimentary basin has low electrical resistivity less than 10m. The crystalline basement is of high-resistivity with depth from 12-24km. The middle and lower crust is of more or less low-resistivity with depth from 12-24km. The crystalline basement is of high-resistivity with depth from 24-47km. The upper part of the lithospheric mantle is of low- resistivity of about 10 m with depth from 47-88km. The lower part of the lithospheric mantle has higher resistivity with depth from 88-138km. The asthenosphere has very low resistivity of 4 m. Except the Manjar depression, its upper and middle crust do not contain any developed low- resistivity layers, crustal average resistivity turns to a slight high, the Moho discontinuity is not clear, and there is a high-resistivity root supporting the basin reaching depth of 80km. These facts show that the Tarim basin should belongto the craton type. However, the terrane is surrounded by steep lithospheric faults, contains high-resistivity blocks all around without movement from depth 15kmto 90km. These facts also show that the Tarim basin should belong to the fault-sunken type. As a matter of fact, the Tarim terrane was a continental craton drifting along a ocean in the Paleozoic, and then faulted and sunken becoming a basin owing to continental collision and compression afterwards. Thus we may call it as a large fault-sunken craton basin. The Manjar depression within the basin is a low resistivity block from depth 15km down to 90 km, and develops a low resistivity loophole in its northern boundary into Tien Shan。We infer that this low resistivity block was created during the closure of the Paleo-Asian ocean in the late Paleozoic, caused by collision between the Tarim, Kazakhstan terranes and Siberia craton. The Manjar, Hetain, Yecheng-Sache, Yutain-Mingfeng and Tangguzibas depressions are all crustal low resistivity blocks, showing active fluid movement. They can be potential areas for oil/gas exploration.