學習表現為教育社會學中的重要議題，其中城鄉間的學習表現差距受到重視。過去研究認為家庭背景與地區的教育資源是影響學生學習表現的主要因素，然而這些研究缺乏班級因素與同儕效果的分析。因此本研究使用台灣教育長期追蹤資料庫（Taiwan Education Panel Survey, TEPS）在2001年與2003年的國中生樣本，以階層線性模型（Hierarchical Linear Modeling, HLM）分析國一班級同儕學習投入對國三數學表現的影響，學習投入以學生為課業所付出的時間為指標。分析結果發現：(1)學生數學表現的總變異中有24%來自班級因素的影響，76%為學生因素。(2)國三數學表現、個人學習投入與班級同儕學習投入有城鄉差距。(3)在控制其他變項下，個人學習投入、班級同儕學習投入對數學表現有正向效果。(4)班級所在地區的都市化程度透過班級同儕學習投入間接影響國三數學表現。 / Academic performance has been an important topic of research on educational sociology for a long time, while urban-rural differences have been already well documented in literatures. In the past, the literature indicated that the key factors to affecting academic performance are family background and the educational resources. But these researches have ignored the factors of class level and peer effects. In this study, the data are from Taiwan Education Panel Survey (TEPS) in 2001 and 2003, use Hierarchical Linear Modeling (HLM) to assess how peer engagement affects junior high students’ mathematics performance. The time students spend in studying is an index of engagement. The main finding are: (1) This research model accounts for 76% of the variation in student level and for 24% of the class variation in class level with regard to mathematical performance. (2) Students in the urban and rural city show a differences in their mathematics performance, student’s own engagement and peer engagement. (3) When controlling variables, student’s own engagement and peer engagement have positive effect on mathematics performance. (4) Urbanization levels indirectly affect mathematics performance through peer engagement.