Abstract The purpose of this investigation is based on the revision model proposed by Ferris , Adams, Kolodinsky, Hochwarter, Ammeter,(2002).This research is deeply to examine the influence of perceptions of organizational politics on trust - organizational cynicism as mediator variable .The data were analyzed by SPSS 15.0 software and by structural equation modeling (SEM). The major results of this study are as following¡GThe perceptions of organizational politics were found have a significant negative relationship with trust. The perceptions of organizational politics were constructed from three patterns( general political behavior¡Bgo along to get ahead¡Bpay and promotion).Only general political behavior has a significant effect on trust.The other two patterns have no significant effect on trust. The perceptions of organizational politics were found have a significant positive relationship with organizationl cynicism . Organizationl cynicism has a significant negative relationship with trust.Organizationl cynicism has a mediating effect on the relationship between perceptions of organizational politics and trust. Key word¡Gperceptions of organizational politics , trust , organizationl cynicism , structural equation modeling