The epsA gene (Gene ID:11997253) of Riemerella anatipestifer (RA) was isolated in our laboratory. By using bioinformatics tools, the biological characteristics of epsA gene and EpsA protein was analyzed. The epsA gene was a 900-bp complete open reading frame, encoding EpsA protein of 299 amino acids. The relative molecular weight of EpsA protein was 32.676 kDa, and theoretical isoelectric point of 7.74. The EpsA protein, located at the outer membrane, had a N-terminal signal peptide between the 1st and the 23nd amino acids, a 23-amino-acid hydrophobic transmembrane domain at C-terminal region, and five probable B cell epitopes located at residue 23-32, 65-69, 127-131, 191-198, and 262-267. By PROSITE searching, nine N-myristoylation sites, seven Casein kinase II phosphorylation sites, two Protein kinase C phosphoraylation sites, and four N-glycosylation sites were found. These results of bioinformatic analysis provided rational data to elucidate biological features of epsA gene and EpsA protein, and could guide experimental research on biological function of EpsA protein.