From the view point that some toxic substances produced in tissue by tuberculous infection might be responsible for the development of the histologic change characteristic to tuqerculosis, the author analyzed the tissue components and succeeded in extracting the substances having strong hemolytic power from the organs of the animals infected with tubercle bacillus. These substances were found in the ethanol extracts of lymph nodes and spleen. Removing alcohol by evaporation, the residue was dissolved in a small quantity of etheralcohol and then precipitated by adding aceton dividing into the aceton-soluble and insoluble frations. Repeating this process the yellow amorphous powder was obtained from the aceton soluble fraction and the light brown viscous substance from the aceton insoluble fraction. Both of them proved to have the strong hemolytic power. And it is suggested that these substances may give some influences on the development in the morphologic change of the tnberculous inflammation.