This paper focuses the attention on some issues of Web-based fuzzy knowledge management systme. In the recent years, fuzzy theory has been an important research field of knowledge engineering. It provides a fundamental theory to deal with the linguistic information of human intelligence mathematically. On the other hand, the second-generation Web that based on XML technology is expected to extend the Internet heyond information delivery to knowledge management. To join together the advantages of both technologies, three major works are accomplished in this paper. First a distributed system model of fuzzy knowledge management based on XML technology is proposed. secondly, the structure of the fuzzy knowledge base is deeply analyzed for defining a fuzzy DTD. Finally, a prototype of DTD for creating fuzzy knowledge base by XML is developed.