本研究旨在探討運用同儕互評於寫作教學，對國一學生寫作動機及寫作表現有何影響，本研究利用行動研究法，兼採質化與量化的資料蒐集方式，以研究者所任教的國一學生為研究對象，於為期八週之寫作課程中，進行四次同儕互評的循環活動。研究對象在實驗進行前後各以「寫作動機量表」測量，且完成一篇紙筆作文，依據「作文評分量表」評分，作為前、後測，並透過教學札記、訪談、回饋表、學生作品等質性資料，進行分析、對照與比較，以了解其在寫作動機與寫作表現的改變。研究主要發現如下: 一、學生對於同儕互評抱持正面肯定的看法。 二、運用同儕互評於寫作教學對學生的寫作動機有正向效果。 三、運用同儕互評於寫作教學對學生的寫作表現有正向效果。 四、透過本行動研究，教師的專業知能更精進且教學態度更加開放。 根據上述研究結果，研究者進一步提出建議，希望本研究成果能對未來教學實務與後續相關研究有更具體的參考。 This study aimed at exploring and analyzing the effects of peer-review on 7th graders’ motivation and writing performance in composition. This research applied an action research methodology using both qualitative and quantitative techniques for data collection. The target subjects of this study were a group of 7th graders in a school where the researcher teaches. In the period of eight weeks of instruction, each student conducted 4 cycles of peer reviews. Two major scales: An Inventory of Writing Motivation and An Inventory of Writing Performance, were adopted in order to measure the shift of students'' motivation and performance before and after the experiment. As for the qualitative approach, teaching journals, oral data from interviews, feedback forms, and the students'' writings were collected in order to make a comparison with the quantitive results. The findings include: 1.The students held a positive view of peer reviews. 2.Through peer reviews, there was a positive effect on the writing motivation of the students. 3.Through peer reviews, there was a positive effect on the student''s writing performance. 4.With the implementation of this action research, the researchers have become more knowledgeable and optimistic about such teaching strategies. Based on the above mentioned results, the author makes several suggestions that can possibly contribute to teaching practices and studies in the future.