Through a quantitative meta-analysis of 39 studies which were published, the determinants and moderates of organizational citizenship behavior(OCB). Determinants of OCB such as extroversion, neurocism, cynicism, work value, high need, task interdependence, organizational justice, job satisfaction, and organizational commitment are included in the analysis. Also business type(service, manufacturing), characteristics of the organization(profit, non-profit), evaluation subject of OCB(self, supervisor), OCB factors(1, 2, 5), and numbers of studied organization(single, two or more) are included as moderators of OCB. The results shows that in general, determinants of OCB were considered as the same results with the extant study. Moderating effects of OCB also shows as expected. Thus in the future study the moderating factors should be considered to study organizational citizenship behavior. In addition, moderating effects might be caused by the strength of associations, not the direction. This study also discusses the meaning, practical implications, and future research ideas related to such major empirical findings.