Abstract:[Objective] To understand the impact of genetic polymorphism of FnBPA-A on the immune biological characteristics of Staphylococcus aureus.[Methods] Sequence of FnBPA-A of Staphylococcus aureus isolated from bovine in Xinjiang was analyzed and 8 different genetic polymorphism eukaryotic recombinants of FnBPA-A were constructed. C57BL/6 mice were immunized with these recombinant plasmids and mice sera were collected. Level of the immune protection of immunized mice was compared.[Results] GS801, GS819 and GS856 were on the same branch; GW10-1, GW20-2, GY288 and GY309 belong to the same branch; GY278 was on a different branch. For the challenge experiment, GW20-2, GS801, GS819, GS856 and GY288 showed better protection.[Conclusion] The genetic polymorphism of FnBPA-A could significantly affect the immune protection of immunized mice.