Abstract: Objective To prepare and characterize monoclonal antibody against a malaria vaccine candidate， PfCP-2.9 chimeric protein of Plasmodium falciparum. Methods BALB/c mice were immunized with PfCP-2.9，and the spleen cells were used for fusion with SP2/0 cells. The monoclonal antibodies were analyzed by ELISA，Western blotting as well as growth inhibition assay. Result A monoclonal antibody was obtained. It interacted with the PfCP-2.9 recombinant protein by ELISA and Western blotting. The interaction of the monoclonal antibody with the protein was reduction-sensitive，indicating that the antibody recognized a conformational epitope. Moreover，the antibody also recognized the cultured parasites of P.falciparum by indirect immunofluorescent antibody test（IFA）. When tested by growth inhibition assay，the antibody significantly inhibited parasite growth in vitro of 56% inhibition rate at the antibody concentration of 0.3 mg/ml. Conclusion A monoclonal antibody against PfCP-2.9 malaria vaccine candidate has been obtained，which recognizes a conformational epitope of the protein and natural protein.

Key words: Plasmodium falciparum, Malaria vaccine, Monoclonal ntibody, Immunodominant epitopes