To obtain the immunized mouse spleen cells, we immnnized the female BALB/C mice I.P. with schizonts or merozoites of the cultured blood forms of Plasmodium falciparum. The immunized spleen cells were fused with the SP2/0 myeloma cells, by which we obtained two strains of hybridoma secreting monoclonal antibodies against human Plasmodium falciparum. Using indirect immunofluorescence assay, we identified that the antibodies reacted only with the surface membrane antigens of the schizonts. These hybridomas were cultured continuously in vitro for over ten months and stably produced antibodies-IgG. The two hybridoma cell lines were designated as AEB2 and AGA4, and the number of their chromosomes was 98 and 100 respectively. The hybridoma cells were injected I. P. into the paraffin oil treated BALB/C mice to obtain the hybridoma ascitic fluid containing monoclonal antibodies. The ascitic fluid inhibited the growth of P. falciparum in vitro up to 89%. The inhibition test showed that antibodies were protective.