This study examines Chinese international doctoral students' academic socialization into TESOL discourses and communities. Rooted in the academic discourse socialization theory, complemented by the notions of Lave and Wenger's "community of practice," and Bourdieu's "capital," "habitus," and "field," this longitudinal multiple-case study suggest the focal participants' academic discourse socialization is mediated by their participation in communities of practice, different forms of capital, and habitus in exerting agency. The participants are socialized into academic discourses and communities through their interactions with more experienced colleagues. By participating in the communities of practice, the focal students gain different forms of capital and experience different degrees of competence and memberships. However, due to the inequitable power relations in the TESOL doctoral program field, each participant is socialized to varying levels of central, peripheral, and marginal participation. This study concludes by providing suggestions for action to be taken by university advisors, instructors, and administrators.