本研究實施問卷調查，以瞭解弱勢學生與一般學生在師生關係、社會支持與學習任務價值的差異，並探討弱勢學生的師生關係與社會支持，對學習任務價值的關係。本研究採叢集取樣，共回收問卷弱勢學生491份及一般學生1,682份。經採多變量變異數分析及結構方程模式後，首先，發現弱勢學生與一般學生的師生關係互有優劣，惟宜多關懷弱勢學生以減少衝突關係。其次，中低以下收入及單親學生所獲得社會支持較一般學生少。最後，良好的社會支持與正向師生關係有助於提高弱勢學生的學習任務價值，且良好的社會支持還能夠促進良好的師生關係，更加提高學習任務價值。 This study used questionnaires to analyze the differences of teacher-student relationships, social support, and task value between disadvantaged students and nondisadvantaged students, and to investigate the relationships among disadvantaged students' social support, teacher-student relationships, and task value. A total of 491 questionnaires for surveying disadvantaged students and 1,682 questionnaires for surveying non-disadvantaged students were returned. Multivariate analysis of variance (MANOVA) and structural equation models were used for data analysis. Several crucial results were found. First, the disadvantaged students' conflict dimension of teacher-student relationships is higher than that of non-disadvantaged students, but the disadvantaged students' instrumental help dimension of teacher-student relationships is lower than that of non-disadvantaged students. Second, disadvantaged students of lower income and single-parent families receive less social support than non-disadvantaged students do. Finally, disadvantaged students' teacher-student relationships and social support substantially affect their task value.