Method and system for recommending context-aware services based on user relationship

The present invention provides a system for recommending context-aware services based on relationships comprises a service providing system and a recommending system.The service providing system directly provides a social network service for users or connects to the social network service directly or indirectly, collects user status information through the user terminal, retains service items, and collects and retains grades of the users for the service items. The service recommendation system comprises a user relationship query unit obtaining information of members which compose the social network relationship of the user through the service providing system according to a service recommendation request; a user status query unit obtaining the user status information from the user terminal through the service providing system; a grade query unit obtaining grade information given to previous service items by the social network relationship members from the service providing system, under a specific condition equal to the current status of the users; a grade estimating unit generating a rating conversion grade decided by familiarity between the user and the social network relationship members of the user, generating grade vectors composed of the service item grade under the specific status, and estimating an expected grade for at least one of the services, which the users have not experienced, by using an aggregate function based on similarity between the grade vector of the users and the grade vector of the members; and a service selecting unit providing the result of the selected recommendation service based on the estimated expected grades.