In recent years, increasing attention has been paid to the roles that assessment plays in promoting learning. Formative assessment is considered a powerful strategy for improving student learning; however, its learning potential has been less extensively explored in contexts where summative assessment dominates, because summative assessment is believed to undermine the effective implementation of formative assessment. The present article explores the potential of using tests formatively in a test-dominated context (i.e., formative use of summative tests). The study adopted a qualitative approach. Data were collected from three classes in a Chinese high school through classroom observations and interviews. The findings revealed that tests were used to a certain degree to improve student learning through test follow-up strategies. Situated in a context dominated by high-stakes tests, the present study provides a contextualised perspective of formative assessment and contributes to the understanding of how summative assessment may be used formatively.