Abstract: This research aims at a power generation system with low environmental load using the dissociation and expansion characteristics of CO2 hydrate (CHR). In the proposed power generation system, actuators are driven using large pressure difference in the CHR generation and dissociation reaction caused by small temperature difference of several tens of degrees. In this paper, we report the results of experiments using reaction vessels of multiple metals on the relationship between thermal conductivity of reaction vessel and the CHR generation characteristics. Because it is in the middle of the experiment, the results obtained so far are reported in this paper. From the obtained results, it was confirmed that the increase in the amount of the CHR produced and the dissociation efficiency of the CHR were improved by increasing the thermal conductivity of the reaction vessel.