This paper addresses the problem of churn-nodes' frequent joining and leaving in structured P2P. We introduce a new P2P model (FS-Chord) with fractional steps joining to keep low maintenance overlay in high churn rate. According to node's participating level, all FS-Chord nodes are divided into Free Nodes (FNs) and Whole Nodes (WNs). FNs rely on WNs in the system and they are excluded from the overlay topology. After the first step is completed, a timer is set up. When the set time is exceeded .. the FN performs the second joining step and becomes a WN. This method can reduce maintenance overhead and improve system stability. Simulation results have shown that the proposed scheme decreases the average number of messages when nodes joining or leaving the system.