Blood serum obtained from twenty-five pregnant cows and five non-pregnant cows in group feeding were analyzed for the determination of vitmin A by carr-price reaction and vitamin E by the ferric chloride bipyridyl reacton. The pregnant groups were determined periodically throughout pregnancy. The results obtained were as follows: 1. The mean value of serum vitamin A concentration in pregnant groups was 160.06±3.788 IU/100㎖ and in non-pregnant group 156.6±19.778 IU/100㎖. The blood vitamin A values for the pregnant groups range from 90 to 222 IU/100㎖. 2. The difference of vitamin A level between pregnant groups and non-pregnant group was not significant. The change of serum vitamin A level in pregnant groups revealed the tendency of increase till the sixth month of gestation but thereafter the value was slightly decreased at the tenth month of gestation and no differences were observed. The correlation between month and serum vitamin A concentration during gestation wasr=-0.326 and a liner regression equation y(serum vitamin A levels, ㎎/100㎖)=155.4+0.78×(month). 3. The mean value of serum vitamin E concentration in pregnant groups was 0.604±0.2534㎎/100㎖ and in non-pregnant group 0.640±0.0672㎎/100㎖. The blood vitamin E concentration for the pregnant groups range was 0.40-0.84 ㎎/100㎖ 4. The difference of vitamin E level between pregnant groups and non-pregnant group was not significant. The change of serum vitamin E concentration in pregnant groups revealed the tendency of decrease as gestation progresses and significantly dropped at the sixth month, thereafter, the value was slightly increased at the tenth month of gestation but no differences were observed. The high correlation between month and serum vitamin E concentration during gestation was r=-0.506 (p$lt;0.01), and a liner regression equation was y(serum vitamin E concentration, ㎎/100㎖)=0.6544-0.084×(month).