The past few decades have foregrounded cooperative learning and its pedagogical implications for students' academic, psychological, and social gains, particularly, in the Western context. These gains, nonetheless, were sometimes questioned and doubted in the Confucian Heritage Culture (CHC) countries such as China. This study adopts Norton's investment model and seeks to investigate Chinese postgraduate students' experiences of cooperative writing in English as a Foreign Language (EFL) classrooms in a local context. The focus is particularly on the mechanism of Chinese students' engagement/disengagement with cooperative learning and the multiple influences on it. Analysis of the data set, which includes five focus group interviews with postgraduate students from a local university in mid-western China, shows that Chinese students' group engagement patterns may vary and be closely linked with their current and imagined identities/communities that engagement in cooperative writing could bring to them. Implications are then drawn to better realize the potential of cooperative learning in the identified context and beyond.