Abstract
With the development of Internet, network has become a important platform for information publishment and communications. However, there are tremendous resources in the network, thus it's very difficult for users to find the wanted resources. Search engine can help them find the related information. When users input some keywords, the search engine will return all the web pages related to the keywords in a reasonable order with some sort algorithm. In this process, retrieval results sort algorithm plays a significant role of user satisfaction. This paper starts from the background of sort algorithm, and introduces the history and development of retrieval results sort algorithms. Then three popular sort algorithms are presented, including PageRank algorithm, Hill Top algorithm and HITS algorithm. According to the disadvantages of PageRank algorithm, we propose an improved algorithm based on concepts. Lastly this paper discusses the possible applications of the improved algorithm.