Abstract: For unstructured P2P network resource search algorithm’s inefficiency and excessive amount of redundant messages, combining with the characteristics of unstructured P2P network topology, this paper proposes a Complete Binary Tree Based on Interest （CBT-BI） unstructured P2P overlay network topology. It establishes a logical connection between the nodes of high similarity of interest, descending order in complete binary tree by their  similarity values of interest; in the process of resource search, it uses bidirectional resources search algorithm based on flooding algorithm. Simulation results show that the topological structure allows the nodes to find the resources in a short time, decreasing the query message, shortening the average routing path, improving the efficiency of resource search.

Key words: unstructured Peer to Peer（P2P） network, topology, interest of node, complete binary tree

摘要： 针对非结构化P2P网络中资源搜索算法搜索效率低、冗余消息量过多等问题，结合非结构化P2P网络拓扑结构特点，提出一种基于节点兴趣的完全二叉树（CBT-BI）非结构化P2P覆盖网络拓扑结构。在兴趣相似度高的节点之间建立逻辑连接，根据兴趣相似度值在完全二叉树中按序排列;在资源搜索过程中，使用基于洪泛算法的双向资源搜索方法。仿真结果表明，该拓扑结构使得节点能在短时间内查找到有效的资源，减少查询消息量，缩短了平均路由路径，提高了资源搜索效率。

关键词: 非结构化P2P网络, 拓扑结构, 节点兴趣, 完全二叉树