Employee initiative and creativity is increasingly important due to the pursuit of creativitiy in knowledge economy. In academia, the study of extra-role behavior, which includs voice behavior, attracts much attention recently. Voice behavior is a kind of communicaiton behavior which is status-unconstrained, change and improve-oriented. Based on 379 corporation employees in sourthern Jiangsu province, the study explored the impact of trust within organization on voice behavior in the perspective of social exchange. The results showed that, trust in colleague, in direct supervisor and in organizaiton, can facilitate employee voice behavior. Moreover, trust in direct supervisor influenced employee voice behavior partially mediated by trust in organizaiton. The positive relationship between employee voice behavior and one's own task performance was found.