Disclosed is a humanized antibody comprising: a heavy chain variable region comprising the complementarity determining region amino acid sequences of SEQ ID NO:1, SEQ ID NO:2, and SEQ ID NO:3； and a light chain variable region comprising the complementarity determining region amino acid sequences of SEQ ID NO:4, SEQ ID NO:5, or SEQ ID NO:6； or a human CD44 binding fragment thereof； wherein said humanized antibody specifically binds the same epitope or epitopes of human CD44 as the isolated monoclonal antibody produced by the hybridoma cell line H460-16-2 having ATCC Accession No. PTA-4621. Also disclosed is the use of the antibody or human CD44 binding fragment thereof for the preparation of a medicament for treating a human breast or prostate tumor.
