Samples of blood were taken from 293 cows and heifers in Koheung, Chonnam, which was dsignated as a place for breeding pure-bred Korean native cattle. Each animal was examined clinically and parasitologically and with the history available considered to be normal at the time of blood collection. The hematology and biochemistry values were determinded, and comparisons were made between three age groups, using the results obtained. All the values obtained were within physiological range : except the alanine aminotransferase values which were higher(P<0.05) in young than in mature or old group of cattle, no significant differences were notred between age groups.