This chapter aims to present a solid theoretical rationale and a conceptual framework for the present study. Based on the previous scholarship, sections 3.1, 3.2 and 3.3 introduce definitions of identity, teachers’ identity and then language teachers’identity respectively. Language teachers’ identity is delineated, including definitions, core components and shaping factors. Then, section 3.4 presents the results of holistic review of current literature on language teachers’ identity research. Following the literature review, section 3.5 critiques the existing studies and points out the research gap which necessitates this research. Finally, in section 3.6, a conceptual framework and working definition that guide the present study are reviewed.