1. A system for managing media contents, comprising: a text classifier, adapted to: classify subtitle information of a media content to be marked according to defined subjects, and obtain content clips of different subjects; and a media content marking unit, adapted to: mark specific time of playing each content clip of a different subject after contents are classified by the text classifier, obtain the content clips which have specific time information and different subjects, match the content clips with concepts in an ontology library, and mark the content clips through terms defined in the ontology library.