The present invention relates to a method and system for constructing a database (DB) based on mutual relations between pieces of video data. The present invention provides the method of constructing a DB based on mutual relations between pieces of video data, including 1) generating one or more nodes so that pieces of identical video data are included in an identical node, 2) generating pieces of node information about respective generated nodes, 3) comparing comparison target video data with pieces of video data of the respective nodes, and then setting relations between the comparison target video data and the pieces of video data of the respective nodes, and 4) updating pieces of node information about the respective nodes, based on the set relations, and also provides a DB construction system using the method.