Abstract: The present invention provides two T-cell epitode peptides of anti-idiotype antibody 6B11 of ovarian cancer, the sequences of which are shown in SEQ ID NO:3 or 6. The present invention also provides the use of such T-cell epitope peptides in the manufacture of vaccines against ovarian cancer and in the treatment and prevention of ovarian cancer. The T-cell epitope peptides of the present invention could specifically kill ovarian cancer cells which are OC166-9 positive, and could find a wide use in the treatment and prevention of ovarian cancer.