The education reform movement has turned its attention to teacher education in recognition of the key role played by teachers. It is important that teacher preparation programs be designed to promote the process of professional identity formation in pre-service teachers. This study describes the professional identity of pre-service teachers in a changing teacher education in Taiwan. The factors related to the process of professional identity development are also examined. Forty-one participants selected purposely from one college for teacher education completed semi-structural questionnaires. Results showed that the majority of participants had achieved occupational identity yet still engaged in professional exploration. The following perceived factors limited advancement to professional identity; personal beliefs and efficacy judgment, the uncertainties of educational policy, curriculum and teaching for teacher education institution and the social value. Implications for enhancing pre-service teachers’ professional identity are also discussed.