1. A system for tracking a moving object, comprising: an acquisition unit configured to acquire a plurality of frames in time series; a detection unit configured to detect a plurality of moving objects from the frames; an extraction unit configured to correspond each of the moving objects among the frames, and to extract a tracklet of each moving object corresponded; a control unit configured to store the tracklet of each moving object corresponded; a setting unit configured to set a frame to calculate a position of a moving object to a notice frame; a grouping unit configured to group the frames into a first block including at least the notice frame, a second block positioned before the first block in time series, and a third block positioned after the first block in time series; a correspondence unit configured to acquire a secondary tracklet included in the second block from the control unit, and to correspond the secondary tracklet with tracklets included in the first block and the third block, based on a similarity between the secondary tracklet and each of the tracklets; and an association unit configured to associate the secondary tracklet with the corresponded tracklets, as a tertiary tracklet.