Chapter 1 Introduction 1.1 Research background 1.1.1 The worker bees metaphor of university teachers under 40 years old ('gaoxiaoqingnianjiaoshi') 1.1.2 The marginalized cohort of college English teachers 1.1.3 My personal motivation of conducting the study 1.2 Research purposes 1.3 Structure of the book Chapter 2Identity Theories and Previous Studies 2.1 Theories of identity in three major disciplinary areas 2.1.1 Psychological approach to identity: Erikson's theory of identity formation 2.1.2 Sociological approach to identity: Wenger's theory of identity formation 2.1.3 Social psychological approach to identity (individual and collective) 2.1.4 Summary of theories of identity 2.2 Previous studies on teachers' professional identity 2.2.1 Teachers' Professional Identity Research in the Domain of K-12 Teacher Education 2.2.2 Research on professional identity of academics in the domain of higher Education 2.2.3 Language Teacher identity in the Domain of Applied Linguistics and TESOL 2.2.4 Research on occupational identities from a sociological perspective 2.2.5 A summary of literature review and identified research gap with respect to my study 2.3 An integrated social psychological approach to identity 2.3.1 Identity theory by Burke and Stets (2009): a combined theory of structural, individual and interactional perspectives. 2.3.2 Giddens' theory of duality of structuration: a constructive perspective 2.3.3 The possibility and advantages of integrating Giddens' theory of structuration into identity theory 2.4 Definition of key concepts and research questions 2.4.1 Definition of key concepts 2.4.2 Research questions …… Chapter 3 A Qualitative Case Study Chapter 4 Sarah: A Demotivated Teacher Clinging to Her Former Student Identity Chapter 5 Richard : An Idetdistic Academic and Realistic Teacher Chapter 6 Emma: A Pragmatic Teacher and Researcher Chapter 7 Mandy: A Teacher Sticking to Her Own Beliefs Chapter 8 Helen: A Caring Teacher Full of Uncertainties and Searching for Meanings Chapter 9 Identity Construction: Content, Source and Mechanism Chapter 10 Emerging Themes, Significance, Limitations and Directions for Future Research Epilogue Researcher's Reflexivity REFERENCES