<p>Early childhood teachers’ professional identity is critical to defining how teachers work on advancing young children’s learning in society. However, the literature suggests that research on this topic is insufficient in non-Western countries such as China and overlooks the mechanisms underlying teachers’ professional identity. This study is informed by critical realism and includes qualitative interviews and policy document analysis to examine Chinese early childhood teachers’ professional identity perceived by teachers and policymakers. It also employs critical realism to construct theoretical explanations of social interactions and the generative mechanisms underlying those perceptions. Caring, pedagogical, partnership and leadership, and learning roles are identified. Five social interactions and mechanisms are proposed to explain teachers’ professional identity. Implications for research, policy, and practice are discussed.</p>