Today, Organizations needs creating and sharing knowledge for development and this meet in the trusted environment. The Purpose of this research is identifying the influencing factors of knowledge sharing, knowledge creation and organizational trust of staff engineering faculty of university of Tehran. 100 people selected as research sample randomly. Data of this research analyzed by T-test, regression and AMOS. The results show that knowledge sharing and its dimentions between staff is lower than average level and externalization is higher than average level. Combination, internalization nd socialization and also trust to managers is lwer than average.. implicit knowledge sharing factors, trust to managers and socialization have the most importance from the view point staff. But socialization, synthesis and internalization organizational trust have an indirect influence on knowledge sharing and knowledge creation and knowledge sharing have a direct influence on knowledge creation.