Gas hydrates are crystalline, icelike solids formed from water contacted with certain light hydrocarbons and other low-molecular-weight, nonpolar substances under high pressure and low temperature. In this study, methane-propane mixture hydrates were made at various conditions. The reaction rates were experimentally measured at each condition. Structure II-type hydrates were formed up to 7580 kPa at around 280 degrees K from methane containing 3% and 5% propane. The reaction rates for forming hydrates were proportional to the pressure difference between the system pressure and the dissociation pressure. The kinetic model was developed.