Abstract: In order to achieve representation and reasoning of fuzzy spatio-temporal knowledge in semantic Web， a fuzzy description logic F-ALCT(D_fst) supporting fuzzy spatio-temporal concrete domain was proposed. Firstly， a fuzzy spatio-temporal concrete domain D_○fst containing fuzzy spatio-temporal regions and their topological predicates was constructed. And the quantitative computation method of fuzzy topological relationships between fuzzy spatio-temporal regions was presented. Then， the concrete domain D_○fst and temporal operators were introduced to fuzzy description logic Fuzzy-ALC， and a new fuzzy spatio-temporal description logic， called F-ALCT(D_fst)， was proposed. Furthermore， a formal definition of syntax， semantics and knowledge base of the F-ALCT(D_fst) was presented. Finally， an example of F-ALCT(D_fst) knowledge base was given. The F-ALCT(D_fst) effectively realizes the representation of fuzzy spatio-temporal knowledge in semantic Web.

Key words: semantic Web, fuzzy description logic, fuzzy spatio-temporal regions, topological predicates, concrete domain, fuzzy spatio-temporal description logic