Abstract: SSPA genes of six serotypes of Riemerella anatipestifer were amplified with specific primers by PCR.DNA sequencing confirmed that SSPA gene has a ORF(1692bp),encoding 563 amino acid.Molecular analysis of SSPA genes was performed by DNAstar,SignalP V4.0,TM-HMM Server V.2.0,NetNGly c1.0,YinOYang 1.0and NetPhos 2.0.The results showed that the amino acid encoded by the SSPA gene contains one potential N-glycosylation site,one potential O-glycosylation site and 38 potential phosphorylation sites(including 9serine,12 threonine and 17 tyrosine sites),there is no transmembrane area,the signal peptide protein cutting part is between A(ala)in the 19 th and Q(glutamine)in the 20 th.The nucleotide homology of SSPA among different serotypes of Riemerella anatipestifer was 95.7%-100.0%,and amino acid homology was 98.2%-100.0%.