Abstract: A gene (pldA) encoding a 33.0 kDa protein with significant homology to the Escherichia coli outer membrane phospholipase A was identified from Riemerella anatipestifer genome database. The results of this study revealed that this gene encoded an Outer Membrane Phospholipase A (OMPLA) in Riemerella anatipestifer. The recombinant OMPLA protein was expressed and its general biochemical features were also, determined. Methyl Arachidonyl Fluorophosphonate (MAFP) could specifically inhibit the OMPLA activity. These observations suggest that OMPLA could be exploited as a drug target in the bacteria and MAFP may serve as a lead compound for drug discovery against R. anatipestifer.