A simulation method for coupling of plasma reactions and combustion reactions was newly developed in this study. Electron-impact reactions and ion recombination reactions were added to an oxidation mechanism of Methane in order to consider the interaction between plasma and flame. A mean electron temperature of the plasma was calculated by solving Boltzman equations by Bolsig code. Effects of strength of an electric field of the plasma and of composition of the mixture on combustion reaction can be analyzed. The authors succeeded in including both reactions in the same code. However, there are some problems such as limitation of thermo-chemical data for ions and excited species.