Abstract: The therapeutic effects of antimycobacterial monoclonal antibodies on the multiplication of mycobacterium tuberculosis in the spleen of mice were Studied.It was found that high concentration of monoclonal antibodies could strongly inhibit the proliferation of tuberculosis bacillus in mice spleen and that low concentration of monoclonal antibodies weakly inhibited the growth of tuberculosis bacillus in mice spleen. However,when the monoclonl antibodies with aconcentration between the high and the low was used in treatment,the multiplication of tuberculosis bacillus in nice spleen was obviously promoted,The therapeutic effects of the same strain of monoclonal antibodies on different strains of mycobacterium tuberculosis were different.The infected doses of tuberculosis,bacillus also showed an important influence on the therapeutic effects of the monoclonal antibodies.