More attention has been paid to peer feedback and teacher feedback in recent years.The current study investigated the attitude of non-English majors toward peer feedback,studied whether the peer feedback was reasonable and how much peer feedback was incorporated into revisions and explored the effect of employing peer feedback or teacher feedback respectively or combining peer feedback with teacher feedback in an experimental class and a control class by comparing and analyzing cases and a questionare and some interviews.Results showed that most students agreed to the effects of peer feedback,that 83% of peer feedback was reasonable and 65% of all the peer feedback was incorporated by student writers,and that in multi-draft writing,peer feedback only and teacher feedback only had similar effect and peer feedback plus teacher feedback was better while teacher feedback plus teacher feedback didn't have expected effect.