This study was conducted to compare the effects of herb residues (HR) and fermented HR on plasma biochemical parameters and antioxidant ability of lactating sows and their piglets, to provide the basis for their application in sow production. Sixty healthy crossbred sows with similar gestational age during the 2 to 4 parities were used and randomly allocated to one of three groups with 20 replicates. The diets were supplemented with 2 kg/t rice bran (control group), 2 kg/t HR (HR group) and 2 kg/t fermented HR (fermented HR group), respectively. These diets were fed from prenatal 21 days to postnatal 28 days. Six sows per group were randomly selected to sample blood by ear-vein at parturition postpartum 1, 7, 14 and 21 days, respectively. Six piglets per group were randomly selected to sample blood by precaval vein at 7, 14 and 21 days of age. The blood samples were centrifuged to recover plasma for analysis of biochemical parameters and antioxidant indices. The results showed that, compared with the control group, dietary HR supplementation significantly decreased the plasma contents of total protein (TP) and globulin (GLB) of sows at postpartum 7 days and the plasma GLB content of sows at postpartum 14 days (P<0.05), while significantly increased the plasma activities of alkaline phosphatase (ALP) and catalase (CAT) and total antioxidant capacity (T-AOC) of sows at postpartum 1 day, as well as the plasma activities of alanine aminotransferase (ALT) and ALP of sows at postpartum 7 days, the plasma activities of ALT and ALP of sows at postpartum 14 days, and the plasma ALT activity of sows at postpartum 21 days (P<0.05); dietary fermented HR supplementation significantly increased the plasma activities of aspartate amino transferase (AST) and CAT and T-AOC of sows at postpartum 1 day, as well as the plasma activities of AST and ALP of sows at postpartum 14 days (P<0.05); dietary HR supplementation in sows' diet significantly decreased the plasma ALP activity and malondialdehyde (MDA) content of piglets at 14 days of age (P<0.05), while significantly increased the plasma T-AOC of piglets at 14 days of age (P<0.05); dietary fermented HR supplementation in sows' diet significantly increased the plasma ALP activity and T-AOC of piglets at 7 days of age (P<0.05), while significantly decreased the plasma MDA content of piglets at 14 days of age (P<0.05). These findings suggest that dietary supplementation with HR or fermented HR in sows' diet affects the organism's metabolism and improves the antioxidant ability of lactating sows and their piglets.