Peer-to-peer networking is a hot buzzword that has been sweeping through the computing industry over the past year or so. Gnutella, as one of the first operational pure P2P systems, is considered as an important case study for P2P networking. By analyzing the Gnutella network topology data, we can discover both the small diameter and the clustering properties characteristic of "small-world" networks. Based on this, the paper aims at analyzing and predicting the performance of current broadcasting algorithm and proposing an improved broadcasting method on Gnutella. By avoiding the unnecessary message forwarding in the network, flow of network communication is remarkably reduced in the new algorithm.