Abstract: With the rapid growing of WWW, significant progress has been made in search engine research area. The evolvement of search engine and the system architecture for the 3^rd generation are reviewed. More emphasis will be given on some core technologies related to search engines of the 3^rd generation. For example, the massive and efficient web-crawling technology, the method of hyper-link analysis, and the user behavior analyzing technology will be described in detail. In addition, it is also presented the recent research progress of WebGather, which is a typical search engine of 3^rd generation. Several research hotspots for future search engine systems are pointed out in the conclusion.

Key words: World-wide Web, search engine, information retrieval, hyper-link analysis, user behavior analyzing, World-wide Web, search engine, information retrieval, hyper-link analysis, user behavior analyzing

摘要： 论述了三代搜索引擎的发展，着重介绍了第三代搜索引擎的体系结构，详细讨论了该搜索引擎的几个核心技术——大规模搜集技术、超链分析技术和用户行为分析技术。介绍了作者参与研发的第三代搜索引擎——“天网”的研究进展，并指出了搜索引擎未来几个研究的热点方向。

关键词: WWW, 搜索引擎, 信息检索, 超链分析, 用户行为分析, WWW, 搜索引擎, 信息检索, 超链分析, 用户行为分析