The influences of protease on the removal of various protein soils from cotton fabrics were studied. The human epidermal stratum corneum, hemoglobin and casein were used as protein soils. The soiled fabrics were denatured by steaming for 30 min. before washing and laundered using Terg-O-Tometer under washing conditions. The removal efficiency was evaluated by analysis of protein on the fabrics before and after washing by means of copper-Folin method. The relations between the removal and the characteristics of protease were discussed. Also the degradation of protein were examined by microscopy. The seperation of human epidermal stratum corneum after hydrolysis was examined by SDS-PAGE. The results obtained were as follow : 1. The protein from the soiled cotton fabric was removed effectively by adding protease. The removal of protein was increased in proportion to increasing of the enzyme concentration up to a certain point, but it began to decrease above the point. The removal effect was high in the order of casein>human epidermal stratum corneum>hemoglobin. Especially the protein was more effectively removed in ADS solution(pH 9.5) containing enzyme. 2. When protease was used with ADS. the removal of protein was efficiently showed in relatively short time(5~15min.) compared to using ADS only. It is due to the properties of this enzyme that reacts with very short time. 3. Even at low temperature the removal efficiency of enzyme was relatively higher compared with the activity of enzyme. The removal of protein soil was increased up to a maximum near $50^{circ}C$, and then decreased. 4. The removal of protein by protease was improved with the increase of alkalinity in the pH range from 9.5 to 11.0 but it began to decrease above pH 11.0. 5. According to the increase of mechanical agitation, the removal effect was increased. But the removal efficiency of protease was more effective compared with the agitation in detergency. 6. According to the SDS-PAGE separation and micrograph it was confirmed that the human epidermal corneum was effectively hydrolysed by the enzyme added. So the fragments of protein were removed more efficiently by means of the interfacial reaction of AOS.