A cancer antigen peptide comprising an amino acid sequence shown in SEQ ID NO: 1 or 2, or a derivative thereof having the functionally equivalent property is provided. The provided cancer antigen peptide is a partial peptide derived from enhancer of zeste homolog 2, which is capable of binding to HLA-A24 antigen and is recognized by cytotoxic T lymphocytes. The cancer antigen peptide of the invention is useful for treatment and prevention of prostate cancer.