As expectation on academic success is high from parents in Asian societies (Chen & Stevenson, 1989; White, 1993), moving towards inclusive practices in schools received great challenges. Using both quantitative and qualitative methods, this study attempts to study the affective and social outcomes of students in a mainstream primary school in Hong Kong. The sample was 410 elementary students across Grade 3 to Grade 6 level. At the first stage, the academic self concept, teacher-student relationship, social integration, and negative affect were studied by the Assessment Program for Affective and Social Outcomes(APASO) (EMB, 2001). The second stage was interview with school teachers. The sample was studied according to class allocation system with which streaming was used and respective curriculum policy was applied. The findings show that the SEN (N=14) showed no significant difference from the typically developing students. However, students who were allocated in the upper bottom class who were not SEN, as well as the low academic achievers studied in the normal classes, shown to have poorer social and affective outcomes. These students revealed anxiety and tension in their academic study. The 21 low academic achievers who studied a normal curriculum in a normal class setting were identified as trouble makers who created disciplinary problems. The study informs that curriculum tailoring and small class setting (<10) worked well on students with a disability. Recommendations were made on what the school can do to assist students in their school life on both the academic study and psychological well-being.