The study aims to explore the relationships between organization citizenship behavior and job performance, and the moderating effects of job satisfaction and supervisor support on the relationships between organization citizenship behavior and job performance. Data are collected from 184 employees and supervisors of NHI Kao-Ping Branch by the questionnaire. The empirical results can be summarized as following five points: 1. Organization citizenship behavior is positively related to job performance. 2. Job satisfaction is positively related to job performance. 3. Supervisor support is positively related to job performance. 4. Job satisfaction has no moderating effects on the relationships between organization citizenship behavior and job performance. 5. Supervisor support has no moderating effects on the relationships between organization citizenship behavior and job performance.