This study aims to analyze the relation between instructor commentary discourse and revision. For this, 86 drafts and the finished papers, 841 commentary discourses were analyzed. The analysis of the instructor commentary discourse types by their function and topic categories reveals the frequency of DF(62.19%)> EC(14.41%)>EO(8.68%)>DO(3.33%)>DC․SC(2.97%), The most discourse type was to indicate the errors of the form of the composition and to instruct how to revise them. The analysis of the extent of the reflection to revision of the commentary discourse by their function reveals the frequency of directing(88.33%), suggesting(52.78%), evaluating(50.97%), questioning (33.88%), and emoting(0.00.%), The analysis of the extent of the reflection to revision of the commentary discourses by their topic reveals the frequency of form(68.65%), organization(61.94%) and content (29.20%). Based on the research finding, this study suggests four proposal. They are as follows：1) Commentary discourse should be cooperative and dialogic. 2) Commentary discourse should be made to expose the context of the evaluation and questioning. 3) Directing discourse should posses the characteristic of the persuasion genre. 4) Subsequent dialogic processes such as question-answer, counsel and discussion are needed.