The positive psychological capital (consisting of efficacy, hope, optimism, and resilience; simply PsyCap) has been conceptually and empirically demonstrated to be related to employee performance. But previous research are limited concerning the causal relation among PsyCap and worker`s attitudes, The purpose of this article examines the causal relation among PsyCap, organizational commitment (OC), and organizational citizenship behavior (OCB), The summary of results of hierarchical regression analysis, based on sample of 354 university/college staffs in Korea: First, PsyCap was a significant positive effects on OC. Second, PsyCap was positively related to extrarole OCB. Finally, OC acted a part mediator between PsyCap and OCB. In addition, this study extends PsyCap research into a new organizational setting - a nonprofit organization. The majority of work on PsyCap has been focused on more profit organizations. Thus, this study also offers some support for the generalizability of the effects of PsyCap. In particular, this review concludes with implications for future research, limitations of this study, and practical application.