While a number of previous studies have examined the effects and benefits of computer-mediated communication (CMC) peer feedback, little research has taken an action research approach to track the process of EFL students' learning in CMC peer feedback. In this article, we describe an action research project conducted with 26 second-year students majoring in business English at a Chinese university. This project aims to enhance EFL students' engagement with peer feedback activities and to help them improve their writing through CMC peer feedback. The analysis of multiple sources of data including questionnaires, interviews, blog-based peer comments, student writing assignments, classroom observations, and teacher reflections illustrates how blog-based CMC peer feedback can be a pedagogical and collaborative learning activity in EFL writing classrooms and how peer feedback training can enhance students' engagement with peer feedback tasks. Implications for implementing CMC peer feedback in EFL writing contexts are provided in the paper.