To clarify the regenerative mechanism of endometrium after parturition in cows, mRNA expression profiles in bovine endometrium were investigated during postpartum period. after PVP-I treatment in cows. The differentially expressed genes in the endometrium between postpartum days 49-52 and days 99-101 were 23 genes, and they were much lower than those before postpartum days 49-52. This result suggests that endometrial regeneration after parturition is completely accomplished until postpartum days 49-52. Overall design: To clarify the gene expression in bovine endometrium at different period after parturition, 4 female cows were used. The endometrial tissues were collected 4 times from the same individual. Several endometrial tissues were biopsied using uterine biopsy forceps from the uterine horns on 9-11, 29-32, 49-52, and 99-101 days after parturition.