The purpose of this study is to investigate involvement in leisure activities by the solitary elderly in Sanchong City, factors influencing their participation, and their satisfaction to those activities. 180 solitary elderly were surveyed in the study, including all the members in the managed cared lists of the Sanchong City Office who survived the study period. Personal interviews were conducted from 2009.7.1 to 2009.8.31 using structured questionnaire. The completion rate is 72.8% with 131 completed interviews. Major results were listed below: (1) The elderly at issue occasionally engage in leisure activities but lack enthusiasm and regular pattern of participation. (2) The diversity and frequency of leisure activities engaged by the elderly who live alone in Sanchong City are relatively low. The leisure activities chosen are mostly sedentary, with socializing as the number one choice. Physical pastime activities are less favored, and the most popular physical activities are strolling. (3) The factors affecting the participation by the solitary elderly include: (A) In terms of population characteristics, the older, better educated, and financially stronger solitary elderly are more enthusiastic in leisure activities. (B) With regard to health conditions, the healthier are more active. (C) As to social relationships, the solitary elderly in Sanchong City interact mostly with their neighbors, companions of physical activities and social workers. Analyzing from social relationships scale, they remain socially active, which indicates that the solitary elderly enjoy social activities and are willing to regulary participate in leisure activities as long as they have company. To sum up, in order to enhance their willingness to engage in leisure activities, those activities should be specially designed based on factors such as the elderly's age, health conditions, and social relationships.