Some of P2P live streaming service encourage sending chunks of peers by changing quality of the video. In this case, peers connect each other and call each other as neighbors. However, the existing neighbor selection method has an issue. If peers that have high capacity for sending chunks has only low capacity peers as neighbor, the peer receives worse video quality than the peer might receive. We call this issue as peer's isolation. In this paper, We propose NSBTB, the neighbor selection method considering the capacity of the peer in order to eliminate isolation to reduce the difference between quality of high capacity peers. In NSBTB, each peer will notice own capacity to neighbors. And each peer selects a neighbor that has more capacity based on neighbor's capacity information. The simulation results show that this method is useful when there are less total amount of capacity of participating peers than all amount of the full video rate on the service.