This longitudinal study examines the use of a mandatory learning module in an initial teacher education (ITE) programme that aims to develop the practical knowledge of pre-service teachers (PSTs) in a Chinese Normal university. Guided by formative interventions, data were collected from videotaped discussion meetings, teaching activities, and reflective journals of PSTs. The data were then analysed from the theoretical perspectives of expansive learning and the components of teachers' practical knowledge. The results identified the intervention trajectory as three consecutive cycles and the intervention outcomes as different development trends among knowledge components in PSTs' practical knowledge. This study contributes to the methodology of formative intervention and its empirical utility, and therefore has global implications for ITE transformation by regarding teacher practical knowledge as a complex knowledge system with evolutionary dynamics.