With the development of society and economy, the competition among enterprises has become increasingly fierce. Apart from land and fund, knowledge has become an important strategic resource, and has been valued by innovative organizations. A lot of researches and practices have been done by managers and researchers about how to promote individual knowledge sharing behavior. However, in reality, knowledge sharing hostility is a common phenomenon in enterprises including knowledge hoarding (knowledge hiding), knowledge rejecting and negative sharing failure experiences This phenomenon is largely due to individual factors. For instance, individuals tend to maintain their knowledge intentionally or unintentionally to hoard with their own competitive advantage; they tend to reject foreign knowledge and create their own in order to pursue professional pride or doubt the credibility of others' knowledge; they tend to have a negative attitude towards sharing negative knowledge and experiences because of the potential career threats posed by sharing their own failures. These phenomena hindered the healthy development of the organization seriously. Therefore, it has become the focus of researchers to understand the traits and psychological mechanism that affect this phenomenon and to implement some effective intervention measures accordingly. Dark personality is considered as a kind of social malicious personality with self-promotion, emotional indifference and aggressive behavior tendency. It is because of its dark side that its influence on counter-productive behavior is attracting researchers' attention increasingly. Individuals with dark personality will act selfishly, coldly and unethically towards the organization and their colleagues, and show more uncooperative and even counterproductive knowledge behaviors. This trait has a far greater impact on the negative production behaviors in the enterprise than the big five personalities. Motivation, emotion and social relations are the main intermediary variables while personality traits affect work behavior. Since interpersonal relationship is a kind of social interaction relationship, individuals, will produce different motivations for different interaction models. Social interactions with positive motivation produce positive results whereas social interactions with negative motivation produce negative results. Meanwhile, the interpersonal relationship will affect the level of trust of the individual to others, so the dark personality will act on interpersonal trust through the interpersonal relationship, thus affecting the knowledge sharing hostility. Based on the 'Trait-State-Behavior' model, this study examines the mediating effects of employee’s relationship and interpersonal trust on dark personality and knowledge sharing hostility, adopting the Dirty Dozen Questionnaire, the Interpersonal Trust Questionnaire, the Employee’s Relationship Questionnaire and the Knowledge Sharing Hostility Questionnaire to survey 307 enterprise employees. Amos software is used to verify this theory model, and the fitting index of the whole model was good (χ2=435.758，χ2/df=2.046, RMSEA=.058, CFI=.906, IFI=.908, GFI=.893).The results show that: (1) Dark Triad can significantly positively predict instrumental relationship and knowledge-sharing hostility (β=.76, p<.001; β=.31, p<.05), and significantly negatively predict affective relationship (β=-.24, p<.01). (2) Instrumental relationship significantly positively predicted knowledge sharing hostility (β=.35, p<.05); Affective relationship significantly positively predict interpersonal trust (β=.78, p<.001), and interpersonal trust significantly negatively predicted knowledge sharing hostility (β=-.35, p<.05). (3) Affective relationship and interpersonal trust play a chain mediator role between Dark Triad and knowledge-sharing hostility; Instrumental relationship play a partial mediator between Dark Triad and knowledge-sharing hostility. According to the results, Dark Triad can directly affect knowledge sharing hostility, indirectly affect knowledge sharing hostility through affective relationship and interpersonal trust, and indirectly affect knowledge-sharing hostility by acting on instrumental relationship.