Since the ultimate goal of adoption is to provide children a happy life in a stable family environment, our major concern is children’s happiness and well-being after adoption. While similar previous studies focused on adjustment and developmental outcomes, little research has investigated adopted children’s happiness and what factors affect it. Therefore, this study aims to examine the happiness of adopted children and identify factors contributing to variations in happiness. The research model was constructed based on ecological theory with the addition of adoption variables to determine whether adoption factors affect their happiness. The second wave data of the quantitative longitudinal investigation on the development of adopted children were used for the hierarchical regression analysis. Child characteristics (gender, age, and disability), adoption-related variables (older child adoption and child’s feeling about being adopted), family (household income and relationship between parents and child), school (academic achievement and school adjustment), and community (environment) characteristics were entered into the model sequentially. The child’s feelings about being adopted were significantly related to their happiness when this factor was first entered into the model. However, its significance disappeared once all variables were considered in the final model; in this case, only children’s disability, parent–child relationship, and school adjustment were significantly related to their happiness. The findings of the study suggest that adopted children’s relationships with family, friends, and teachers are more important to happiness than the adoption itself. The implications for social practice in adoption fields were discussed based on study results.

由于收养的最终目的是让孩子在稳定的家庭环境中过上幸福的生活，所以我们最关心的是孩子在收养后的幸福和幸福。虽然以前的类似研究侧重于调整和发展结果，但很少有研究调查收养儿童的幸福感以及影响它的因素。因此，本研究旨在检验被收养儿童的幸福感，并找出导致幸福感变化的因素。该研究模型基于生态学理论构建，加入收养变量以确定收养因素是否影响其幸福感。收养儿童发展定量纵向调查第二波数据用于层次回归分析。儿童特征（性别、年龄和残疾）、收养相关变量（年龄较大的孩子收养和孩子对被收养的感觉）、家庭（家庭收入和父母与孩子之间的关系）、学校（学业成绩和学校适应）和社区（环境）特征依次输入模型。当这个因素第一次进入模型时，孩子对被收养的感觉与他们的幸福感显着相关。然而，一旦在最终模型中考虑了所有变量，它的重要性就消失了；在这种情况下，独生子女的残疾、亲子关系和学校适应与他们的幸福感显着相关。研究结果表明，收养儿童与家庭的关系，对幸福而言，朋友和老师比收养本身更重要。根据研究结果讨论了收养领域的社会实践的影响。