Purpose: “Teach with Fun After-School Care Service (TWF)” was an educational mentoring program developing character traits among primary school students in the form of school-based mentorship, provisioned under a wider intergenerational project. This study aims to examine the effectiveness of the program on character traits development among primary students. Methods: Two multi-school controlled pretest–posttest trials were conducted in primary one through three across two school years between 2016 and 2018. Among students, 37 (34.6%) were of ethnic minority and with special educational needs. Treatment group of 107 students were compared with 53 in comparison group on traits of self-control, responsibility, cooperation, kindness, and courtesy. Results: Results demonstrated interaction effects between time and group for self-control (p = .026), responsibility (p = .038), and courtesy (p = .042). Discussion: This research provides evidence for TWF’s intervention model and offers implications for intergenerational programs. Findings enrich cumulative knowledge about desirable social outcomes in education setting.

目的： “以有趣的课后托管服务（TWF）教学”是一项教育指导计划，以校本指导的形式发展小学生的性格特征，并在更广泛的代际项目下提供。本研究旨在检验该计划对小学生性格特征发展的有效性。方法：在 2016 年至 2018 年的两个学年中，在小学一到三年级进行了两次多学校对照前测-后测试验。在学生中，37 名（34.6%）是少数民族和有特殊教育需求的学生。治疗组107名学生与对照组53名学生在自制、责任、合作、善良和礼貌等方面进行了比较。结果：结果表明自我控制（时间和组之间的相互作用效应p = 0.026），责任（p = 0.038），和礼貌（p = 0.042）。讨论：这项研究为 TWF 的干预模式提供了证据，并为代际计划提供了启示。调查结果丰富了有关教育环境中理想社会成果的累积知识。