Adopting a self-study approach, the paper drew on the first researcher’s life history, her 17-year teaching career in particular, to explore the features of an EFL teacher’s personal practical knowledge (PPK) constructing as well as the impact of self-knowledge on this process. The findings indicated the two features of the first researcher’s PPK construction: 1) shifting focus between curriculum knowledge, pedagogical knowledge, student knowledge, contextual knowledge and teacher’s self-knowledge at different career stages, and 2) a tendency towards cooperative learning and integration of teaching and research. Through the theoretical lens of “possible selves”, the research revealed that motivation to bridge the gap between hoped self and current self while simultaneously avoiding the feared self is the major drive for teachers’ PPK construction. To meet the demands of hoped self, teachers would employ different means to increase PPK. The study may offer insights into college English teachers’ professional learning and the research method highlights the potential of using the self as resource in pursuing professional development.