Firstly,the proactive Chicken Breasts policy to ALM tree which is based on Chord DHT was extended and a back-path scheme with which each node pre-calculates a backup path for itself was proposed.When the non-leaf node leaves,all its child nodes can switch to the respective backup path immediately.Moreover,the ChordM-FR protocol which based on Chord and adopts the Back-Path scheme was developed.The simulations demonstrated that the ChordM-FR can bellows reconstruct ALM tree about 2.5 times faster on average than the ChordM-SR which adopted the reactive policy in reconstructing multicast tree.