This experiment was carried out to analyze the fractionations of whey protein in colostrum and normal milk from Korean heifers and cows by Sephadex G-100 gel filtration. `The results obtained are summarized as follows: 1. By Sephadex G-100 gel filtration with 0.02M phosphate buffer, pH7.0 whey protein elution in colostrum and normal milk from heifers and cows were fractionated into 4 fractions; F-1, F-2, F-3 and F-4 fraction. 2. The proportions of F-1, F-2, F-3 and F-4 fraction in colostrum whey and normal milk whey were 48.17 and 35.71%, 28.58 and 40.93%, 18.68 and 20.63%, and 4.57 and 2.37% in heifers, 37.49 and 31.98%, 30.20 arid 42.22%, 26.79 and 25.48%, and 5.53 and 0.32% in cows, 42.83 and 33.85%, 29.39 and 41.58%, 22.74 and 23.06%, and 5.05 and 1.53%, in total average, respectively. There were significant differences (P$lt;0.01) in the proportions of F-1 and F-3 of colostrum whey between heifers and cows. 3. The proportions of F-1 fraction in colostrum whey by 1st day after parturition were significantly (p$lt;0.01) decreased while the proportions of F-2 and F-3 fraction were significantly (P$lt;0.01) increased, as the days after parturition passed. The proportions of F-4 fraction in colostrum whey by lst day after parturition and normal milk whey were similar.