The motivation of students to study is crucial to a teaching process, which contributes to shaping student’s attitude vis-à-vis what he/she is learning. Formative assessment, together with curriculum content design and teaching methodology, is recognised as one of the key factors facilitating motivation enhancement. The insights of formative assessment lead stakeholders to the right decision whether to apply formative assessment in one another way. A study on formative assessment literature gave a theoretical frame to mirror how the reality meets criteria. To investigate this reality, we conducted a survey of 116 lecturers and 228 students at three teacher education universities in Vietnam based on Yamane Taro’s simplified sample selection formula. Then the data were analysed by using the software SPSS to produce the percentage, mean value and standard deviation of each answer group. The results show important positive and negative impacts of formative assessment on English major’s motivation. Thence some solutions are suggested to improve student motivation and the quality of English teacher-student training.