This paper conducts a literature review on the purpose, criteria, and procedure of principal evaluation. And then based on the literature review, this paper designs a principal evaluation system for the junior high and elementary schools in Republic of China. The purposes of the system are: (1) to develop the professional quality of principalship, (2) to make the personnel decision for principals. The criteria of the system include five areas, namely policy implementation, instructional leadership, administrative management, interpersonal relationship, and professional characteristic. The procedure of the system has three phases which are evaluation planning phase, formative phase, and summative phase.