The purpose of this study is to understand the current volunteer programs of the Taiwan Power Company (TPC) as case-study. The research problem focuses on the characteristics of the volunteer participants in TPC; if the volunteers' personal backgrounds affect their motive for engaging in volunteer service and also if the social environment affects their participation? how does the level of volunteer participation affect their motive for volunteering services? By using the cross-sectional quantitative research method, the research also conducts case analysis on the strategic planning of the sustainable participation of the volunteer program, and on indicators to the sustainable development of the program. The hypotheses applied to this research include personal background as variable which would affect participants' motive for volunteering and the social environment within the program; the level of volunteer participation would influence their motive for volunteering; participants' motive for volunteering and the social environment within the volunteer program arc correlated with each other. This research found that of all the volunteers 1).76% are female; 2).Most of them (43%) are in the pre-elderly stage (between the age of 55~64), while 21% are in the early elderly stage (between the age of 65~74); 3).Most of them (50%) are of senior high or vocational school background; 4).87% are married; 5).Most of them (41%) are housewives; 6).206 volunteers (77%) have religious beliefs; 7).Most of the volunteers' household monthly income is between NTD$ 10,000 to 30,000; 8).Most of them are currently living with their spouses and children; 9).Most of them believe they're of good physical health; 10).Most of them serve 4-6 hours weekly in the program; 11 ).Most of them have served in the program for over 5 years. The research concludes to increase the scale of TPC retiree volunteer program; to enhance volunteer service quality with volunteer education and development training; and regularly to host recreational activities and public recognitions for the volunteers to boost their morale; to advice TPC to invest in the human resources for volunteers; and to propose a practice in sustaining volunteers' participation to the program. The research also suggests TPC to create a planning group to deal with volunteer program-related issues, and invite local professionals of experienced volunteers for their guidance and participation, and to better manage volunteers' service target.