Abstract: [Objective] The research aimed to study the changes of T-SOD activity and MDA content in the serum of small-tailed Han sheep in perinatal period. [Method] 20 2～5 year-old small-tailed Han sheep were selected, including 10 pregnant ewes and 10 non-pregnant ewes. The blood samples was collected on the 20th, 10th and 1st d before parturition and the 1st, 10th, 20th d after parturition to measure T-SOD activity and MDA content in the serum. [Result] T-SOD activity in the serum of small-tailed Han sheep showed the dynamic change trend of first decrease and gradual increase in the whole perinatal period. T-SOD activity on the 1st day before parturition was lowest and T-SOD in the serum of small-tailed Han sheep in perinatal period was all lower than that in non- pregnant ewes. MDA content in the serum of small-tailed Han sheep in perinatal period showed the dynamic change trend of first decrease and gradual increase in the whole perinatal period. MDA content on the 1st day after parturition was lowest and T-SOD in the serum of small-tailed Han sheep in perinatal period was all higher than that in non- pregnant ewes. [Conclusion] The pregnancy and parturition had some influences on T-SOD activity and MDA content of small-tailed Han sheep.