While automated writing evaluation (AWE) programs are becoming a readily available pedagogic option for second language (L2) writing instructors, the important question of whether the use of AWE would impact teacher feedback remains largely unexplored. This study investigated teacher feedback practices in response to the adoption of AWE in a mainstream L2 curriculum in China. Informed by the mediated learning experience (MLE) theory and drawing upon semi-structured interviews, responses to a questionnaire, classroom observations, and AWE records, this study observed that the impact of AWE was manifested in changes not only in feedback mode, amount, types and levels, but also in the intentionality, reciprocity, transcendence, and meaning dimensions of teacher feedback. The findings also show that such impact was further mediated by individual teacher beliefs about AWE and students, teacher willingness to offer scaffolding and contextual factors. This study suggests that with teacher and contextual supports, AWE systems can be taken as important sociocultural artifacts mediating the integration of MLE as a new object of teacher feedback activity in writing classrooms. These findings call for attention to how more transformative teacher feedback can be promoted with the use of AWE.