An outbreak of duck septicemia caused by Pasteurella anatipestifer was studied in Chonnam province. The outbreaks of duck septicemia has become an economically important disease in duck farm. The present study undertaken to identify the etiological agent of duck septicemia and to evaluate the efficacy of bacterin against P anatipestifer in Chonnam province during period from May to December 1996. The results obtained were as follows ; 1. The distribution of etiological agents from collected 328 duck samples were Pasteurella anatipestifer(57%), Escherichia coli(21%), duck viral hepatitis virus(4%), Salmonella sp(1%) and others (10%). 2. The agglutination titers of autogenous vaccine were increased after End vaccination and reached highest at 5-6 weeks post inoculation at the titers of 6.0-4.0.