：以Napster和Gnutella为代表的文件共享软件已经成为Internet上增长最迅速的应用。这种运行于多个对等结点（Peer）之上的网络被称为对等网络。随着对等网络规模的增长，可扩展性成为迫切需要解决的问题也成为了研究的热点。本文综述了对等网络领域的研究现状，首先介绍了Internet上常见的对等网络系统及其局限性，然后对最近提出的多种支持大规模对等网络的分布式哈希表查找系统进行了综述，介绍了基于这些查找系统的新一代的文件共享系统，讨论了对等网络中的安全问题并指出了进一步的研究方向。-The Napster and Gnutella file-sharing software represented has become the most rapidly growing Internet application. This runs on a number of peer nodes (Peer) over the network is known as peer networks. With the growth of network size, etc., scalability is an urgent need to address the issue has become a research hotspot. This paper reviews the research on the status of such networks, first introduced on the popular Internet peer network system and its limitations, and then a variety of recent large-scale peer networks to support distributed hash table lookup system was review, introduced a new generation of systems based on these to find the file sharing system, discussed on other network security issues and that further research directions.