The present invention provides a humanized anti-human α9 integrin antibody having improved activity and/or property as compared to a donor mouse anti-human α9 integrin antibody, namely, a humanized anti-human α9 integrin antibody containing a heavy-chain variable region consisting of the amino acid sequence shown by SEQ ID NO:11 and a light-chain variable region consisting of the amino acid sequence shown by SEQ ID NO:17, a humanized anti-human α9 integrin antibody containing a heavy-chain variable region consisting of the amino acid sequence shown by SEQ ID NO:13 and a light-chain variable region consisting of the amino acid sequence shown by SEQ ID NO:17, a humanized anti-human α9 integrin antibody containing a heavy-chain variable region consisting of the amino acid sequence shown by SEQ ID NO:15 and a light-chain variable region consisting of the amino acid sequence shown by SEQ ID NO:9, and a means for the prophylaxis or treatment of various diseases involving human α9 integrin in the pathogenesis, which uses the antibody.
