Since we organized the committee to control hospital infection in April 1980, we have adopted various investigations and strategies. When wide spread of infection caused by Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa was recognized in 1981 our strategies were set up of water faucets with footpedal, frequent to wash of hands and use of disposable paper towels. Investigation of HBV markers revealed that the positive rate of HBV antibody was 21% in scrub and ward nurse group. Vaccination was performed to our HVB antibody negative members to protect them from the infection of HBV antigen. After HBV antigen positive patients were operated, we sterilized the operating room using our ultraviolet ray irradiation apparatus. In 1990, 50 cases infected with MRSA were detected bacteriologically, which occupied 68.5% of all those infected with Staphylococcus aureus. Therefore, we cultured MRSA from nose swabs and investigated numbers of bacteria in the air which were gathered with air sampler in the operating rooms and wards.