Abstract: Riemerella anatipestifer disease could induce huge damage to the duck industry. It is necessary to establish fast simple and sensitive method due to the backward of present conventional methods. According to published OMPA ATCC strains OMPA gene sequence in GenBank, a pair of genespecific primers in a conservative region was designed by DNAstar software, PCR method was started initially from taking only one of Riemerella anatipestifer colony directly. Fifteen clinical isolated strains include RA1,2,10 and 11 as well as four reference strains include RA1,2,10 and 11 could be amplified the specific 670 bp fragments while E.coli, Pasteurella multocida were negative. Sensitivity test results showed that the PCR detection minimum limit was 80 Riemerellaan atipestifer CFU. The results of newly established colony PCR and conventional PCR method were the same, both could amplified the same band, it proved that the colony PCR method was deserved for further research and application．

Key words: colony PCR, conventional PCR, Riemerella anatipestifer, OMPA