Anti-idiotypic monoclonal antibody (Mab Ab) by MAb COC166-9 against ovarian serous papillary adenocarcinoma was prepared. Hybridomas of Abscreened by sandwich ELISA and immunocompetitive inhibition tests were procured and named as 6B11 and 1H12. The number of their chromosomes were 93 and 91, and DNA analysis also proved the characteristics of hybridomas. These Abs could induce delayed type hypersensitivity (DTH), the cellular immune response. The results of the immune reaction of 6B11 with SKOV3 (ovarian carcinoma cell line) were similar to OC166-9 (Ag), the positive control, while 1H12 was weaker. Anti-anti-idiotypic antibody (Ab) was also raised by 6B11 and 1H12 respectively. They all showed positive immunohistochemical stainings with ovarian serous adenocarcinoma tissue sections and immunocytochemical stainings with SKOV3 cells as was shown by COC166-9. In the antibody dependent cell mediated cytotoxicity (ADCC) tests, the) showed no differences against SKOV3 as compared with COC166-9. We a