Guided by cultural border crossing and teacher identity development theories, this case study explores the bumpy process of a junior Chinese faculty member's border crossing into the U.S. teaching culture and analyzes the challenges, coping strategies, and consequences of his border crossing on teaching and teacher identity development. The study found the subject demonstrated an active process of adaptation during his border crossing and experienced multifaceted and ongoing identity development in which both Chinese culture and the culture that he embraced played important roles in reshaping and facilitating the development of his professional identity, teacher learning, and teaching practices.