The present invention provides humanized antibodies that immunospecifically recognize human 9 integrin. Some of these antibodies inhibit the biological functions of the 9 integrin, thereby exhibiting therapeutic effects on various disorders or diseases that are associated with 9 integrin, including cancer, e.g., the growth and metastasis of a cancer cell, and inflammatory diseases, e.g., rheumatoid arthritis, osteoarthritis, hepatitis, bronchial asthma, fibrosis, diabetes, arteriosclerosis, multiple sclerosis, granuloma, an inflammatory bowel disease (ulcerative colitis and Crohn's disease), an autoimmune disease, and so forth.