Objective:To produce monoclonal antibodies against Bacillus anthracis PA15,and preliminarily establish double antibody sandwich-ELISA to detect the protective antigen obtained from serum of patient infected with Bacillus anthracis. Methods:Purified PA63 proteins were performed as immunogen to immunize mice. Hybridoma technology was performed to produce monoclonal antibodies. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to detect the purity of antibodies. Indirect ELISA,Western blot,immunoprecipitation (IP) and protein profiling were performed to analyze the specificity of monoclonal antibodies. Furthermore,double antibody sandwich-ELISA method was performed. Results:Two monoclonal antibodies against PA15 were obtained,named 3D7 and 8E9. SDS-PAGE showed the heavy and light chains of antibodies. Indirect ELISA and Western blot detected that monoclonal antibodies 3D7 and 8E9 can specifically bind PA15 and PA63. IP and protein profiling analyses showed that monoclonal antibody 3D7 can specifically bind PA83. Double antibody sandwich-ELISA detected that the limited detectable concentration of protective antigen from serum infected with Bacillus anthracis was 16 ng/ml. Conclusion:We have successfully developed monoclonal antibody against PA15,and established double antibody sandwich-ELISA to detect anthrax infected serum protective antigen.