Bovine mastitis was examined by use of the rolling ball viscosity test in Kwang-ju area. Antibiotic sus-ceptibility of isolated pathogens from raw milk was investigated by the disc method. Positive rate of so-matic cell counts (over 500,000 cells/ml) was decreased from 11.1% in 1991∼1993 to 8.0-% in 1995∼1997. Isolated mastitis-causing-pathogens were identified as Staphylococcus sp. (49.7%) Escherichia coki(23.2%) Streptococcus sp. (10.4%) and Bacillus sp(7.2%) Antibiotic susceptibility of isolated pathogens to almost antibiotics was decreased.