Abstract: The present study tries to explore three aspects concerning teacher professional identity construction and answer these questions: 1.How do university EFL teachers in Vietnam understand their professional identity? 2. How do university EFL teachers in Vietnam construct their professional identity in community of practice? The university EFL teachers who participate in the present study are from a university in Thai Nguyen, Vietnam. They are divided into three groups and are categorized as beginner teachers, teacher development and experienced teachers.