This paper studies a possibility of introducing a 2-cycle methanol diesel engine power generation plant. Since methanol is much in vaporizing latent heat and small in quantity of heat emission per unit weight when using it as fuel, observed are a decline in combustible range temperature and a large decrease in NOx emissions. As for thermal efficiency, generating end efficiency of 46% is expected by heat recovery in the case of 40-50 thousand kW class 2-cycle engines. The methanol engine has such excellent performance/characteristics as little lowering of efficiency at middle loads, possible numerical control, short starting time and high load change rate. The construction cost is approximately equal to that of the LNG steam power generation and is lower than that of the LNG combined cycle power generation. The unit power generation cost is lower than those of fuel cells and gas turbines and 2-3 yen/kW higher than those of the combined cycle and the reformed turbines. However, it is found that methanol engines are most suitable to meet 200MW class demand. 52 refs., 68 figs., 19 tabs.