Embodiments of the present invention disclose a method for content categorization, where the method comprises transmitting, by a content categorization request entity, a categorization ability negotiation request to a content categorization providing entity to request the categorization ability of the content categorization providing entity; receiving the categorization capability of the content categorization providing entity returned by the content categorization providing entity. Furthermore, embodiments of the present invention disclose a system for content categorization, content categorization request entity and content categorization providing entity. Categorization ability negotiation or subscription helps to learn the content categorization ability so that the content categorization request entity or content categorization providing entity may mutually and accurately acquire content categorization capability information without delay.