The influences of the detergent containing protease, oxidation or reducing bleaching agents upon the removal of denatured blood protein stains were studied by using the fabrics soiled with hemoglobin and serum albumin treated with heat. The solubility and dispersibility into water of the denatured blood proteins stained on the fabrics were remarkably decreased compared with those of undenatured one. The removal efficiency of those stains were also fairly low during the washing by detergent containing protease. By contrast, the removal efficiency of denatured blood protein stains was remarkably high, if an oxidation bleaching agent containing chlorine such as sodium hypochlorite having strong oxidation action was used at the concentration of above 300 ppm under the washing conditions of pH 9.5 and 40°C in temperature. However, when sodium hypochlorite alone was used to remove the denatured blood protein stains at 25°C, it was difficult to obtain high-degree removal effect, because the concentration of sodium hypochlorite in the washing solution was limited to the concentration of 50-200 ppm that was applied commonly to the bleaching by considering the damage for the fabrics. The removal efficiency of denatured blood protein stains was relatively high, if the two bath method was adopted combining the washing with detergent containing protease and the washing with sodium hypochlorite.