This study aims to research the influencing factors of self-disclosure in social network sites (SNSs). Although much has been reported on the issue of influence factors of self-disclosure, very few have been discussed from the aspect of environment stimulus. Drawing upon the Privacy Calculus model and the Stimulus-Organism-Response paradigm, we developed an integrated model to investigate the impacts of SNSs features as environment stimuli on users’ perceived value and subsequently their self-disclosure behavior. The results indicate that self-disclosure in SNSs is determined by the tradeoff between perceived benefits (relationship management and enjoyment) and costs (privacy risk). And users’ perceptions of SNSs features (interactivity, personalization and privacy control) have significant impacts on perceived value and self-disclosure behavior.