Objective:To investigate the H5N1 avian influenza antibody level in occupational exposure population in Jiangsu province during the beginning of the influenza A (H7N9) outbreak. Methods:The antibody levels of Hong Kong,Guangdong and Anhui strain were detected using serum hemagglutination inhibition(HI) tests. The results were converted into geometric mean titer (GMT) and analyzed. Statistical analysis of the influencing factors of antibody levels was performed. Results:The difference was significant between antibody levels of different gender and antigen strains of all 416 serum samples tested. Conclusion:Our study showed that the antibody level of H5N1 avian influenza is low,and the levels of male are not as high as those of female. HI antibody level of Guangdong strain is closer to currently epidemic strains of avian flu in Jiangsu Province.