The reputation system is used to display the reputation of entities based on the ratings or appraisals given by users who have used or purchased those entities. Web service providers supply various reputation systems for their users. However, these promising reputation systems face some challenges. First, even though different persons have different preference and values (values are a person's beliefs about what things are good or bad), these systems still give the same rating to the same entity for all users. Second, they may be greatly influenced by Sybil attacks. In this paper, we propose a reputation system, called values-based reputation system (VRS), to solve the aforementioned problems. VRS customizes the rating of an entity for each user based on the ratings of the entities provided by other users who have similar values or preference to the user. Experimental results on 256 users show that compared with existing reputation systems VRS is more robust to Sybil attacks and provides a recommendation rating that is closer to the rating given by the user after it used the related entity.