"Teacher education aims at promoting teachers’ knowledge for facilitating students’ learning. Teaching research strives to explore teachers’ knowledge as teaching mediation. First, this paper indicates that teacher education had emphasized competence-based knowledge rooted on process-product approach in Taiwan for a long time. 12-Year Educational Reform proposed transforming competence-based towards new competences. With the viewpoint of cultural-historical activity theory (CHAT), the reform of teacher education isn’t the change of fragment knowledge but of continuous innovation. In the next sections, this paper discusses the development context of CHAT, interpreting the features of teaching with the stance of CHAT, and proposing essential teaching competences for teacher education."