A total of 298 strains of Staphylococcus aureus isolated from chicken staphylococcosis of different types were subjected to 26 phages of the International Series. One hundred and ninety-one (64.1%) strains were typable by one or more of the phages at 1, 000 RTD, but only nine of them were lysed at RTD. Of these typable strains, 129 (67.5%) belonged to type III, 40 (20.9%) to mixed types, 17 (8.9%) to type II and 5 (2.6%) to type IV. Frequent lysis were obtained with phages 75, 53, 54, 7, 6, 77 and 3C, and 95.8% of the typable strains were lysed by any one of these phages. There was no significant relationship between staphylococcal phage types and types of disease. Type III strains were commonly found in staphylococci isolated from many chicken farms regardless of districts, and thus, they were considered to be distributed widely among chickens in this country. On the other hand, type II or IV strains were obtained from a very limited number of farms.