Abstract: The elliptic polarization, which is occur with the electromagnetic field in conductive media communication, must been taken into consideration when calculate the magnetic field excitation, In order to get the accurate phase information. In this paper, the basic method of calculating the resistivity by the phase of SNMR which is been studied. Proposed that treat the aquifer and the water content, which are inversed with the Generalized method under the condition of resistivity is unknown, as a priori value in the inversion of resistivity by the phase with the simulated annealing method. The study solved the calculating of resistivity by the phase, which is helpful to further use the phase information and to improve the accuracy of the aquifer and water content in inversion.