This study, drawing upon the approach of narrative inquiry, explores how a student-teacher – Ming – negotiated and navigated conflicting emotions in the process of becoming a teacher. The findings reveal that while Ming experienced some negative feelings in his work, which challenged his self-belief as a teacher, the positive emotions derived from his students’ progress and recognition contributed to his teacher identity. However, due to the constraints imposed by his mentor and the school context, his negative emotions gradually escalated, posing severe impediments to his teacher identity.