The purpose of this study was to evaluate the effectiveness of the third-year mentor teacher program in Taipei, Taiwan, ROC. The research method was a questionnaire survey. According to the survey findings, the positive impacts of the program were: (1) mentor teachers and partner teachers (protégés) were satisfied with their interaction, (2) both vedio recording and teaching portfolio were helpful for the instructional growth of partner teachers, (3) the functions of the program were highly recognized by mentor teachers and partner teachers, (4) mentor teachers and partner teachers were willing to continue their relationships. The problems of the program were found to be the following: (1) the work loading of partner teacher was heavey, (2) menter teachers were not matched with partner teachers who taught the same grade level or subject matter; (3) mentor teachers and partner teachers did not have adequate time for informal and formal conferencing, planning, and conversation. Based on the research findings, some recommendations were proposed to improve the implementation of the program.