From the perspective of the Big Five Personality Model, and adopting innovation diffusion theory and the concept of social value orientation, the effects of personality traits on knowledge sharing, and the moderating effects of intrinsic motivation in a virtual open content community are investigated. The paper uses latent regression and simple slope to make an empirical analysis of a sample of active uses of Wikipedia (N = 304). The results support the notion that knowledge sharing is associated with higher levels of trendsetting and a prosocial value orientation, and a lower level of opinion leadership. Moreover, moderation analyses demonstrate that the effect between trendsetting and knowledge sharing is positively moderated by intrinsic motivations, and the effect between prosocial value orientation and knowledge sharing is negatively moderated by intrinsic motivations.