Authors observed an outbreak of bovine coccidiosis at a farm stock in Gyeongnam, Korea, which were diagnosed on the ground of clinical and fecal examination with the following results. Twenty one of thirty four Korean native cattles evacuate feces containing blood and mucus or evacuate entirely of clots of fresh and red blood. On fecal examination showed eimeria zuernii. The patients were recovered with sulfamethazine and amprolium for 5 days. From these results the outbreak was considered to be typical bovine coccidiosis.