Disclosed herein is a system and method for providing a supplementary information associated with a broadcast content. The system provides a supplementary information associated with a specific broadcast program in the broadcast content by means of a supplementary information server, wherein the supplementary information server comprises a broadcasting receiving unit for receiving the broadcast content; a synchronization information unit for storing a synchronization information of the supplementary information associated with the specific broadcast program; a video comparison unit for comparing screens of the broadcast content with a previously stored scene change screen of the specific broadcast program and setting a start time of the specific broadcast program; a supplementary information extracting unit for calculating an elapsed time from the start time of the specific broadcast program to a specific screen and extracting the supplementary information corresponding to the elapsed time. The supplementary information associated with the specific broadcast program in the broadcast content is provided through the steps of receiving a synchronization information of the supplementary information associated with the specific broadcast program; setting a start time of the specific broadcast program by comparing screens of the broadcast content with a previously stored scene change screen of the specific broadcast program; calculating an elapsed time corresponding to a specific screen based on the start time; extracting the supplementary information corresponding to the elapsed time.