A parametric study on the qualifications of the MHD generator inlet and the criteria for the inlet flow conditions were performed. A quasi-1D approach was utilized in the study to analyze the influences of the load factor, magnetic flux density, and the ionization power density upon the performance and the operating range of the inlet Mach number of the MHD generator. It was found that the performance of the MHD generator would increase at the cost of the reduction of the operating range of the inlet Mach number, and vice versa. Interdependencies among these parameters are investigated, and presented in the present paper. An acceptable measure to enhance the performance of the MHD generator and expand the operating range of the inlet Mach number is then proposed accordingly.