The purpose of this study is to provide the basis for the development of a training program for mentor teachers in Korea. In order to achieve this aim, this study discusses the role and dispositions of mentor teachers, and the knowledge bases and skills which are essential to mentor teacher training. The role of mentor teachers is to provide emotional support and professional assistance for first-year teachers. To perform these role, mentor teachers should have appropriate personal and professional dispositions, and the mentor training programs should include the knowledge bases of adult learners, teacher development, teacher thinking process, and school culture, and the skills, conference management, promoting teacher reflection, and communication with teachers.