Two recovery methods of methane gas from marine sediments with methane hydrate were studied. In order to obtain the dissociation rates of methane hydrate for an accurate simulation of methane production from the methane hydrate-bearing layer, a suitable reaction system must be planed in the laboratory. We made a newly-developed laboratory-scale experimental apparatus as thermal recovery method and depressurization method for production of natural gas. We can measure dissociation rates of methane in the quasi methane hydrate-bearing layer. A dissociation model of methane hydrate was developed that express the methane flux and mass transfer. The dissociation rates of methane hydrate at the surface was determined based on the proposed model using a correlation equation for the surface area of methane hydrate-liquid interface with the experimental results of apparent dissociation rates at thermal recovery method. The methane hydrate was formed with packed particles in the apparatus that can be also obtained the formation rates of methane hydrate at that time, and was dissociated under a given condition of temperature and pressure at both experiments, and ambient water flow velocity at thermal recovery method. The apparent dissociation flux was determined from the time course of volume of methane. The methane hydrate dissociation rates were determined under various flow conditions of ambient water, pressure, and temperature. At thermal recovery method, the methane recovery rates were measured using low-temperature water in view of mass transfer driven as concentration difference of methane between methane hydrate and pure water, and using higher temperature water in view of thermodynamics. At depressurization method, we did the numerical case studies to simulate heat transfer and phase change taken place in the experiment vessel by changing the hydrate surface area.