From a sociocultural perspective, this case study explored two intermediate-level Chinese university EFL students' multi-dimensional engagement with asynchronous computer-mediated mode of peer feedback. Data sources included student drafts, peer feedback, think-aloud protocols, stimulated recall, and semi-structured interviews. The two students displayed different responses to asynchronous computer-mediated peer feedback with different foci when engaging with it affectively, cognitively, and behaviorally. In particular, their cognitive engagement was characterized by noticing and interpretation, evaluation, and decision-making. The two student writers' engagement was not just related to the computer-mediated mode of peer feedback, but also to their motives and roles adopted in the activity of engaging with peer feedback, both of which may be influenced by the community (i.e., the classroom instructional context), its rule (i.e., word limit), and the division of labour in the community (i.e., the role adopted by student reviewer). Pedagogical implications are discussed.