Abstract: For developing an advanced evaluation system to assess nuclear power plant， a number of comprehensive evaluation-decision making methods, including the AHP-weighted summation method, the comprehensive fuzzy evaluation method, are employed to produce evaluation results. By changing the weight factors of evaluation indices characterizing the economics, safety and technology of nuclear power plant, the variations of evaluation with weight factors were studied and the sensitivities of these indices were analysed. Finally, the evaluation results were compared and discussed based on comprehensive analysis.