Class teachers in China have to take care of many student issues, such as academic achievement, morality cultivation, and class management. Drawing upon Margaret Archer's social morphogenesis approach, this study scrutinizes the dimensions of class teacher's professionalism and the general trajectories of class teacher's professional growth. The findings reveal that subject teaching skills work as the foundational competence for credibility, whereas communication and class management are higher-level competences. Empathy and guidance are the necessary abilities at the highest level. Self-reflexivity and the ability to seek institutional support, are crucial drivers for class teacher's growth across levels.