Abstract：In order to solve the problem that BitTorrent (BT) traffic occupies too much import and export bandwidth, a cloned tracker was designed and implemented. In this method, the cloned tracker employed list selection algorithm different from original tracker to return the list, when the BT client sent its list request to tracker. Cloned tracker used list requestion algorithm which was different from original tracker, and returned Peers list instead of original tracker. Cloned tracker fetched and updated the list from original tracker. Finally, on the condition of unmodified BT client and original tracker server, the cloned tracker could efficiently control the import and export bandwidth occupied by BitTorrent traffic in the real network environment.