Proofreading is considered a necessary skill that has been much talked about but rarely taught. In this paper, we will present a study that incorporated proofreading in some EFL beginning writing classes. About 121 second graders participated in this study. Most of the students had had over one year of writing experience prior to this study. In order to foster students' awareness on errors made in their writing, self-and peer-proofreading activities were added to their writing class in Spring, 2008. This study intended to find out if these young writers can proofread their and others' writing as well as what can be learned from such a practice. It is found that these young writers are able to self- and peer-proofread their and others' written work. In addition, we have learned that the students hold positive attitudes towards the proofreading activities; they show awareness of writing mechanics; they employ the ”spelling line” strategy to express ideas; their grammar awareness is enhanced; they revise their peer's work based on their interpretation; and finally, they learn to give and take corrections. The findings shed light on the understanding of the implementation of proofreading in young EFL learners' writing class.