This study investigates how the aspects and effects of each group`s peer feedback could be different through an union of the peer feedback group members by level in a college writing class. For this, college 60 freshmen was classified as homogeneous group in writing level and heterogeneous group. The main result was like the following. First, the heterogeneous group activity was more effective than homogeneous group`s in almost area. Second, a writer who relatively has the lower level of writing in the heterogeneous group was able to get a tutoring from peers who have the higher level of writing. But, in the contrast, a writer who has the higher level of writing tended to correct writing based on the problem detection provided from peers who have low level of writing. Therefore, this study shows that heterogeneous group should be composed to have an effective peer feedback in the college writing. And also we can consider to perform heterogeneous group activity in stages to improve its limit and consider peer feedback workshop with increasing the number of group members including at least two writers who have the higher level of writing.