Two postpartum cows were used to study the ultrastructural changes of uterine endometrium by using scanning electron microscope. The results showed that the process of repair of uterine endometrium after calving was demonstrated by scanning electron microscope through a series of endometrium biopsy. Some part of the endometrium was damaged after calving and its adjacent endometrium cells became necrosis and exfoliated during the first 7 days post－partum;the cilium and microvillus of the epithelial cell in the undamaged area of the endometrium disappeared. By 26 days postpartum the damaged area reduced and the cilium and microvillus increased in their numbers. The damaged tissues were all repaired by day 60 postpartum.