An improvement trial for identification of the Mycobacterium tuberculosis complex by immunochromatographic assay using anti-MPB 64 monoclonal antibodies (MPB 64-ICA) is documented. The new MPB 64-ICA is very useful for simple and rapid identification of the Mycobacterium tuberculosis complex with specificity, but it is a little difficult to prove the Mycobacterium tuberculosis complex on the blood culture samples taken from the immunosuppressive or the AIDS patients, because the reactive bands are red or reddish-purple in both the control and positive zones of immunochromatographic assay, which are often indistinguishable from the background mixed with hemoglobin caused from the blood samples. We tried to remove the hemoglobin interference in the samples and was able to make clear the background with addition of hydrogen peroxide (H2O2). The results are followings; the optimum time and density of H2O2 are from 5 to 15 minutes and 35%, respectively. Accordingly, the improvement trial for identification of the Mycobacterium tuberculosis complex by immunochromatographic assay using MPB64-ICA with H2O2 is useful to identify the positive reactive band from the interference by hemoglobin.