Objective To investigate expression of Human papillomavirus (HPV) 11 type E7 protein antigen in prokaryotic cells and its potential use for the serodiagnosis of condyloma acuminatum (CA).Methods The full-length gene encoding for HPV11 E7 protein was amplified by PCR,and cloned into vector pET32a(+) to form recombinant pET32a(+)/HPVll E7 plasmid.The fusion His-E7 protein was expressed and analyzed by using SDS-PAGE and Western blotting.Using ELISA assay,HPV11 E7 fusion protein were also used to screen human serum IgG antibody from 93 patients with CA,43 patients with cervix cancer and 58 healthy control subjects.Results Highly expressed fusion His-E7 protein was obtained,and purified protein served as a special diagnostic antigen to screen human serum antibody for CA serodiagnosis.It showed that CA group,cervix cancer group and healthy control human serum IgG antibody average value were 1.545?0.131,0.586?0.155 and 0.674?0.150 respectively,positive rate were 76.3% (71/93),11.6% (5/43) and 5.2% (3/58).There was significantly difference between the CA group to compare cervix cancer group and healthy control (P