A total of 108 Holstein calves with an average body weight of l19kg was studied in 4 farms in middle region of South Korea in late Autumn from November 8 to 27, 1991. Individuals were selected for treatment when they exhibited acute signs of pneumonia and had a rectal temperature of$geq$4$0^{circ}C$. Each animal received intramuscularly either danofloxacin at 1.25mg/kg once daily or oxytetracycline at 10mg/kg once daily for three consecutive days. The individuals which had a rectal temperature of$geq$39.5$^{circ}C$ at 24 hours after the third treatment received two further treatments. Treatment for three or five days with danofloxacin was very efficacious and superior to oxytetracycline in the treatment of calve pneumonia. Eighty-six per cent of 58 danofloxacin treated calves and sixty-six per cent of 50 oxytetracycline teated calves responded successfully to treatment for three days and the difference between treatment groups was highly significant. Danofloxacin was more efficacious than oxytetracycline in rapid and complete control of pyrexia and in resolution of clinical signs. The minimum inhibitory concentration of danofloxacin for Pasteurella hemolytica and Pasteurella multocida was equally 0.12~0.50 mcg/$mell$ while that of oxytetracycline for Pasteurella hemolytica and Pasteurella multocida was 2.0~4.0 and 4.0~16mcg/$mell$, respectively. During the treatment period side effect was not found in all animals of both treatment groups except some animals receiving oxytetracycline showed pain at the site of injection.