Social systems, particularly family, school, and peer, are especially critical in influencing adolescents to participate in volunteer service; however, no objective measures of this construct exist. Objectives: This study examined the psychometric properties of the Family, School, and Peer Influence on Volunteerism scale (FSPV) among Chinese adolescents. The FSPV is an instrument that assesses the perceived influence of these social systems on adolescent volunteerism. There are nine identical items for each of the three systems. Method: The FSPV was administered to 2,819 early adolescents in Hong Kong. Results: Confirmatory factor analyses revealed four factors, namely, "Family," "School," "Peer," and "Extrinsic influence." The FSPV also demonstrated good internal consistency, construct validity, and criterion-related validity. Conclusion: The psychometric properties of FSPV are adequate in the assessment of the perceived influence of social systems on volunteer service participation in Chinese adolescents. (Contains 4 tables and 1 figure.)