In order to perform the thermal properties of CO_2 hydrate Monte Carlo simulations have been carried out under constant temperature and pressure conditions. In this paper we discussed two kind of thermal properties like as density and specific heat at constant pressure. The thermal properties have been focused for the clathrate hydrate of CO_2 at temperatures ranging from 150 to 280 [K] and pressure up to 50 [Mpa] in the NPT ensemble using TIP4P effective intermolecular potential model of water. Our results indicated that density depend on the rate of filling factor, on the contrary, specific heat at constant pressure do not receive pressure effect at the same rate of filling condition. Comparisons between MC calculated result and experimental results also are presented.