MT measurement are recently carried out at 71 sites along 3 east—west directio n profil es and 4 north—south direction profiles in the volcanic cluster and the vicinit y to study the magma chamber and deep structure. The preliminary results show that there is a high r es istive body rivetshaped beneath the cluster at the depth between a few hundre ds meters and about 15～20 km. It is postulated that the high resistivity body i s a cooling magma chamber and it passes through crust and connects to the upper m antle. The tip of the rivet body extends continually down to several tens kilome ters and resistivity deceased with increasing depth. The above results can be in terpreted by that the magma came up from the upper mantle. There is not magma ch amber with low resistivity in the crust. The fracture strike is along N —S direc t ion.