Personalization has been recently one of the most important features of intelligent information retrieval. An intelligent system should store information about user interests and utilize this information to deliver to the user documents he really needs. In such a system the information needs of a user should be represented by means of so called a user profile. User profiles, in other hand, should be used together with queries to sort retrieved information in such order that is adequate to user preferences. In this paper a vector-based information system model is presented, in which the user information needs and preferences (profiles) are defined and the methods for updating user profiles and automatic learning about user preferences are worked out.