The purposes of this study are to analyze the relationships among institutional employees’ experience of volunteership, their subjective well-being and interpersonal citizenship behavior, and further to explore the influence and moderating effect of work-family conflict. We analyzed 224 valid questionnaires and obtained the following findings: firstly, the volunteership experiences help employees to increase their subjective well-being as well as interpersonal citizenship behavior than non-volunteers; secondly, employees’ work-family conflict and subjective well-being has a negative relation; and thirdly, as for the moderating effect, employees with lower work-family conflict exhibit a higher interpersonal citizenship behavior than the employees with higher work-family conflict. Finally, we provide both theoretical contributions and practical implications based on the research findings.