Abstract: Reservoir evaluation of gas hydrate based on electrical response, as a key mean to discriminate natural gas hydrate and estimate its resource potential, plays an important role in the exploration and development of natural gas hydrate. The physical simulation experiment for gas hydrate formation in sediments was carried out in this paper to detect the morphology of dispersed hydrate and massive hydrate based on electrical resistivity tomography during the formation of hydrate. The resistivity responses of the two gas hydrate morphology were carefully studied. The results show that the high resistivity of dispersed hydrate has a scattered distribution pattern whereas the high resistivity of massive hydrate distributed in a concentrated pattern. The free gas in sediments may cause the position deviation of massive hydrate. The resistivity response characteristics of dispersed hydrate and massive hydrate change largely. Compared to the dispersed hydrate, the resistivity of massive hydrate increases rapidly with the formation of hydrate.