The key issue in structured P2P (peer to peer) is to locate resources effectively. Chord is a kind of structured P2P system based on overlay network. However, Chord construction doesn?t consider the real network situations. At the same time, the clockwise searching scheme of original Chord doesn?t make good use of the anti-clockwise neighbors? information. All these increase the latency and cost of locating resources. A bidirectional Chord system based on latency-sensitivity is proposed to decrease the latency and cost of locating resources. This system partitions the nodes according to the latencies among these nodes and the landmarks to decrease the average response time. And by the means of bidirectional query algorithm on Chord, the search path length is reduced. Theoretical analysis and simulations show that the system decreases query-response time greatly.