A company's human resource aspect can gain benefit from extra-role behaviours known as organizational citizenship behaviour (OCB). This research discusses about organizational citizenship behaviour (OCB) of the employees at Satria Muda Sucore Agency, an insurance company based in Jakarta, Indonesia. The purpose of this research to analyze the dominant factors that influence organizational citizenship behaviour (OCB) in the company. Factors affecting organizational citizenship behaviour (OCB) are altruism, conscientiousness, sportsmanship, courtesy and civic virtue. The type of research used is descriptive with quantitative method. The respondents were 66 employees of Satria Muda Sucore Agency. The sampling technique using propability sampling with simple random sampling type and using factor analysis method. The results of research showed that organizational citizenship behaviour (OCB) is in the high category. This research formed five factors that are tolerance factor, help behaviour factor, compliance factor, participation factor and loyalty factor. Tolerance factor is the most dominant factor of organizational citizenship behaviour (OCB)