A disintegrin and metalloprotease with thrombospondin domains (ADAMTS) are a member of peptidase and involved in processing of von Willebrand factor as well as cleavage of aggrecan, versican, brevican and neurocan. Among 19 subfamilies of human ADAMTS, ADAMTS-4 is a zinc-binding metalloprotease and is a famous therapeutic target for arthritis. It has been reported that a flavonoid luteolin shows inhibitory activity against ADMATS-4. In this study, we verified that luteolin is a potent inhibitor of ADAMTS-4 and probed the molecular basis of its action. On the basis of a docking study, we proposed a binding model between luteolin and ADAMTS-4 in which 3',4'-dihydroxyl groups in luteolin formed hydrogen bonding with ADMATS-4 and these interactions are important for its inhibitory activity against ADAMTS-4.