This paper investigates the influence of person-supervisor fit on organizational citizenship behavior in service corporations, and explores the moderating effects of personality in the relationship between person-supervisor fit and organizational citizenship behavior. Based on the dyadic view of supervisor and subordinate, it is concluded that person-supervisor fit has a significant and positive correlation with OCB, OCB-self, OCB-interpersonal, OCB-organizational & OCB-society; personality has a significant and positive correlation with OCB, OCB-self, OCB-interpersonal, OCB-organizational & OCB-society. In addition, personality moderates the relationships between person-supervisor fit and OCB-self & OCB-interpersonal, but has no mediating effect in the relation of person-supervisor fit to OCB-organizational & OCB-society.