In China, since 2004, developing students' overall communicative competence has become the central goal of the current College English Curriculum Requirements. However, this goal has yet to be addressed, particularly in regard to the teaching of writing. This paper examines whether and how changes in teachers' knowledge base related to teaching writing may impact their students' writing outcomes. Six experienced teachers were introduced to a SFL (Systemic Functional Linguistics)-informed genre approach and subsequently trialled this pedagogy in practice. Through pre-and post-workshop interviews and classroom observations, changes in teachers' knowledge base were investigated. In each observed class, two writing samples produced by students were collected. The findings of changes in the teachers' knowledge base were compared with possible changes emerging in their students' writing products. The results of the comparison reveal that, corresponding to positive changes evidenced in the teachers' knowledge base, the majority of the students made improvements in their writing products.