Abstract: A large number of information of Decp Web is valued and topi}oriented, it is difficult for us to use knowledge representation formalisms to encode and reason within the uncertain knowledge in Deep Web. The paper presented a method to represent uncertain knowledge in Decp Web using dynamic fuzzy description logic(DFDLs). I}he syntax and semantics of DFDLs were given. Then, we provided a tableau-based decision algorithm for this logic. The DFDLs provides more reasonable logic foundation for the Deep Web uncertain knowledge, and it can present more fuzzy and dynamic information for the Deep Web.

Key words: Deep Web, Uncertain knowledge, DFDLs, Tableau inference