In this work Computational fluid dynamics (CFD)model is developed for analysis of premixed methane-air combustion in constant volume combustion chamber. First CFD model was implemented for natural gas-air mixture and validated with experimental results for pressure-time history from literature. Then CFD model is implemented for analysis of methane-air mixture.For ignition of premixed mixture laser ignition method is used. In this study the variation of pressure versus time is investigated to study the combustion characteristics. Also variation of mass fractions for reactants and products with respect to time was found out from CFD analysis. For CFD analysis commercial CFD solver STAR CCM+ is used.