This study aimed to investigate the effects of 1% distillers"" grains (DG) on reproductive performance of sows in late pregnancy. A total of 72 healthy PIC sows (80 days of pregnancy) were randomly divided into two groups, with 6 replicates in each group and 6 sows in each replicate. The control group was fed a basal diet, and the DG group was supplemented with 1% Fuyu flavor DG in the basal diet. The experimental period was from 80 days of pregnancy to delivery. The results showed that the litter weight, number of live piglets and number of healthy piglets in the DG group were significantly higher than the control group (P<0.05), while the number of intrauterine growth retardation (IUGR) piglets was significantly decreased (P<0.05). DG decreased the content of urea nitrogen in colostrum of sows (P<0.05), but there was no significant difference in immunoglobulin (Ig A, Ig G, Ig M) levels (P>0.05). Analysis on biochemical indicators showed that DG increased the serum triglyceride (TG), cholesterol (TC), high-density lipoprotein (HDL-C), total superoxide dismutase (T-SOD) and catalase (CAT) (P<0.05), but decreased the level of interleukin-2 (IL-2) (P<0.05). Additionally, DG increased the glutathione peroxidase (GSH-Px) level in placental tissue (P<0.01). Analysis on fecal microbiota showed that DG had no significant effect on the intestinal microflora clustering, chao1 index, observed-species, PD-whole-tree and shannon index (P>0.05); however, DG reduced the relative abundance of Spirochaetota and Treponema (P<0.05), and increased the abundance of Clostridiaceae (P<0.05). In summary, supplementation of 1% DG in the diet of sows during late pregnancy can effectively improve the reproductive performance and antioxidant capacity, alleviate inflammation and modulate the gut microbiota structure of sows.