With active aging being the goal of an aging society, how to maintain a meaningful later life for the elderly becomes a critical issue. An important basis for active aging assessment is community participation, through which the psychological well-being of the elderly can be evaluated and the impact on their mental health and their life assessed. On the selection of the population for this study, the target for analysis consists of senior Pingtung County citizens aged 65 or more. Questionnaire survey is administered for data collection. Based on the model derived from the concept of psychological well-being by Ryf(f 1989), this study will explore the relationship between Pingtung elderly's community participation and their psychological well-being. Data from the survey will be tested by multiple regression method. The model showed higher levels of psychological well-being for the elderly who participated in community than those who did not, which again confirmed the positive relation between community participation and psychological well-being.