Peer-to-peer systems have become one of the most popular Internet applications. Some unstructured systems such Gnutella perform file searching by flooding requests among nodes. It has been proven that such unstructured systems are not scalable, and searching consumes tremendous bandwidth. We propose three mechanisms to reconstruct the system topology and improve message flooding. Our research addresses four aspects: system topology control, message routing, message locality, and system connectedness. The simulation shows that significant redundancy in flooding of messages can be eliminated and message locality achieves a high ratio.