Abstract: Current technological status of Web information retrieval (IR) analyzed, we point out the root of its inefficiency is the ranking function and term weighting algorithms searching engine adopted. Then classic IR ranking function and term weighting technologies are introduced. Characters of Web documents studied, the fact is most of them are HTML documents, a kind of structured documents. Its structure is defined explicitly by predefined HTML tags, which has different importance and influence on the performance of search engine. The studies of researchers on structures of HTML documents introduced, that is, making use of the peculiarity of Web documents to extend classic ranking function and term weighting technology to a structured one. Finally we discussed the development trend of these technologies mentioned above.