A social data filtering system is provided. The social data filter system comprises a database, a retrieving module, a filtering module and a determining module. The database stores personal data and corresponding identification information. The retrieving module retrieves the personal data and the identification information corresponding to a designated person and generates search information accordingly to retrieve user information and corresponding social interaction information from a plurality of social data sources accordingly to the search information The filtering module performs filtering on the user information and the social interaction information according to the personal data to retrieve filtered information. The determining module determines at least one key word corresponding to the designated person according to the filtered information.