Magnetohydrodynamic (MHO) power generation is the new method that can reach a very high efficiency. To estimate the effectiveness of MHO generator, this study has calculated the electrical producing cost with the consideration of the normed coefficient of the energy efficiency and the relative expenses for maintenance. As a result, the calculated electrical producing cost was 8.38[cent/kWh}, which was much lower than the purchase price of some countries in the world. When analysing the technical-economic effectiveness, it was seen that the ratio of the investment cost and the fuel price has affected to the effectiveness of MHO power generation system in comparing to that of the traditional power generation system. This result shows that the MHO system is more effective than the traditional system when the natural energy resources are exhausted and the fossil fuel price increases.