A field survey was conducted on the Native Cattle of Korea, to determine the pattern of reproductive performance in general farm and to study the effect of season, province and registration. The least squares were estimated from 6.513 cows raised at general farms in 8 pure-breeding district of Korean native cattle from June, 1984 through November, 1985. The overall means of the respective traits were: age at first estrus, 436.9 days; age at first calving, 809.4 days; age at first estrus postpartum, 72.0 days; calving interval, 383.5 days; the number of AI per conception, 1.51. Normal calving was 94.1%, and abortion and stillbirth comprised 1.7%. The rate of twin calves was 0.5%. Calf mortality during suckling period was 4.5 out of 1000, and cow culling rate was 3.6 out of 1,000.