Serum $alpha$-tocopherol was measured in cattle to evaluate normal range and to investigate the difference of $alpha$-tocopherol levels between healthy cattle and diseased cattle. Seventy two heads of 1 year old beef Cattle have 429.9$pm$77.2 $mu extrm{g}$/100ml of Serum $alpha$-tocopherol. The Serum $alpha$-tocopherol values of calves with diarrhea(8 heads), pneumonia(6 heads) and piroplasmosis(4 heads) were 87.1$pm$19.2, 126.3$pm$45.7 and 106.3$pm$30.9$mu extrm{g}$/100ml, respectively. But that of calves in good health (S heads) was 357.t$pm$68.4 $mu extrm{g}$/100m1. And the values of diseased calves are significantly lower an that of calves in good health(p<0.05). Seasonaly, serum $alpha$-tocopherol levels of dairy Holstein cows were 529.9$pm$ 120.3(March), 540.2$pm$127.2(June), 566.9$pm$149.5(September) and 550,0$pm$ 125.4(December)$mu extrm{g}$/100m1, respectively. The values on autumn was the highest than that of othor seasons. Serum H-tocopherol level of cows with retained placenta was 262.2$pm$40.6$mu extrm{g}$/100m1. And the level of retained placenta was significantly lower than that of healthy cattle regardless seasonal variation(p<0.05).