On the basis of the records obtained from 9,103 head of Korean Native Cows, the effects of the location, generation, pregnancy phase, year of birth and season of birth on body weights were estimated. Least squares means and standard errors of body weights at birth, 4 months of age and 24 months of age were 24.69±0.35㎏, 103.96±3.85㎏ and 354.32±6.94㎏, respectively. The effects of the location, generation and year of bird were highly significant on the birth weight. The location, generation, year of birth and season of birth significantly affected the weaning weight(p$lt;0.01). Also on the weight at 24 months of age, the location, generation, year of birth and season of birth had a highly significant effect(p$lt;0.01), while the phase of pregnancy showed a significant difference at the 10 % level.