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Introduction: In many studies, immunogenicity of Brucella proteins such as P39 in animals is investigated. In this study, we evaluated antigenicity of recombinant P39 from Brucella abortus in patients with Brucellosis. Materials and Methods: In this experimental study, at first recombinant P39 was produced in Escherichia coli. Sera reactivity of six infected individuals against the recombinant P39 protein was analysed by Western Blot. Results: Data indicated that P39 protein from Brucella abortus was recognized by patients, sera antibodies. Conclusion: Our data showed that recombinant P39 protein can be detected as an antigen by sera in infected human. Therefore, recombinant P39 have same epitopes with natural form of this antigen.