Based on operation of WAMS in the power system, evaluation sheme of WAMS is proposed. Evaluation content is divided into three levels, including system hardware, system software basic function and system application function. The three levels’ content are evaluated progressively one by one, and the corresponding evaluation method and evaluation function of every level are designed. Based on the relation of the three levels, the evaluation functions of the whole WAMS master station system are designed. Aiming at the stability and the reliability of the system, the evaluation methods and functions are designed for a certain period. At last based on the above evaluation methods and functions, a quantitative indicator is provided for the WAMS master station system, which reflects the stability, function, and performance of every level and the whole master station system. The real system test shows effectiveness and practicality of proposed methods.