This investigation was performed to isolate and identify Staphylococcus sp. from air at the 25 sites in one hospital in Daegu. Drug sensitivity tests bacteriologically were also studied. The results are summarized as follows: 1. In gram staining of isolated colonies, the number of staphylococci strains was 959(70.2%) among 1367 collected in the morning, and 653(66.2%) among 987 collected in the afternoon. 2. The number of isolates was slightly higher in samples collected from the outpatient treatment rooms and wards in the main building than in samples from the other sites. 3. In biochemical tests of 1612 strains of isolates gram positive cocci, the number of coagulase positive strains was 584(36.2%) and coagulase negative 1028(63.8%). In experiments on growth on mannitol agar containing 7.5% NaCl and mannitol fermentation tests, the number of mannitol fermentation strains was 423(30.8%) and nonfermenter was 951(59.2%). 4. In antibiotic sensitivity tests of 746 identified strains of staphylococci, coagulase positive strains showed resistance in. higher portions to penicillin(89.7%), chloramphenicol(64.6%), gentamycin (52.1%) and tetracycline(45.2%), whereas in lower portions to kanamycin(39.2%) and apmicillin(33.1%). 5. Among coagulase negative and mannitol fermenting strains, higher portions showed resistance to chloramphenicol(76.5%), penicillin(69.8%) and ampicillin(63.6%), whereas lower portions showed resistance to kanamycin(48.8%), tetracycline(39.5%) and gentamycin(34.0%). 6. The number of strains showing multiple resistance to above 6 antibiotics were 15(52(19.8%) among coagulase positive and mannitol non-fermenter and 36(22.2%) among coagulase negative and mannitol fermenter.