Abstract: The aims of this study was to clone and sequence the ompA gene of Bordetella avium, and predict its secondary structure and B-cell epitopes, which provides a theoretical basis for the study of immune mechanism and B. avium subunit vaccine. The B. avium ompA gene was amplified, cloned, and sequenced. By using bioinformatics softwares and methods, the secondary structure and B-cell preponderant epitope of B. avium OmpA were predicted The results indicated that B. avium ompA gene is 597 bp, encoding 199 amino acids. Using three methods, prediction of the secondary structure of B. avium OmpA indicated that random coils were the main structural type of the flexible region in secondary structure, and contain a small amount of α-helix, β-sheet and a rare β-turn. The OmpA protein was supposed contain 5 potential antigen epitopes and 2 potential glycosylated sites. These results provide a theoretical basis for the further study of immune mechanisms, monoclonal antibodies preparation and epitope vaccine design.