The study evaluated the effects of coated folic acid (CFA) and coated cobalamin (CCA) on the lactation Performance, nutrient digestion, rumen fermentation and hepatic lipid content of dairy cows during perinatal period. Forty-eight Holstein dairy cows during perinatal period with similar parity, prcvious 305-d milk yield and body wcight were assigned in a 2 X 2 factorial and randomized block design to 4 groups: cows in the control group were fed a basal dict, and those in other 3 groups were fed basal diets supplemented with CFA 6. 75 g'd, CCA 0.6 g'd, and CFA 6. 75 g • d + CCA 0. 6 g • d, respectively. The study started at 21 days before the excepted calving date and ended at 21 days after calving. During the Postpartum 21 days, body wcight changc (BWC) and lactation Performance were determined, and samplcs of blood, rumen fluid and liver tissue were collected. The results showed as follows: 1) CFA addition significantly decreased the BWC (P<0. 05) and significantly increased feed efficiency (P<0. 05). The yiclds of actual milk, 4% fat-corrected milk (FCM), milk fat and milk protein significantly increased (P<0. 05) with CFA or CCA addition. 2) The apparent digestibility of dry matter (DM) and neutral detergent fiber (NDF) increased significantly (P 0. 05), but total volatilc fatty aeids (TVFA) concentration increased (P<0. 05) with CFA or CCA addition. Rumen acetate concentration and acetate to Propionate ratio increased significantly (P<0. 05) with CFA addition. Rumen Propionate concentration increased significantly (P<0. 05), while acetate to Propionate ratio decreased significantly (P< 0.05) with CCA addition. 4) Blood nonesterified fatty aeids, ß-hydroxybutyrate (BHB) and homoeysteinc (Hey) contents decreased (P0. 05), but folate (FA) content increased significantly (P< 0. 05) with CFA addition. Blood glucose and cobalamin (CA) contents increased significantly (P <0. 05) with CCA addition. 5) Hepatic FA content increased significantly (P<0. 05), and total lipid and triglyceride (TG) contents decreased significantly (P < 0. 05) with CFA addition. Hepatic CA content increased significantly (P<0. 05), but total lipid and TG contents were not significantly changed (P > 0. 05) with CCA addition. 6) Whcn compared with CFA or CCA addition alonc, the FCM yield, NDF digestibility and rumen TVFA concentration were greater (P<0. 05), and blood Hey and hepatic TG contents were lower for cows reeeiving CFA and CCA together. In conclusion, addition of CFA and CCA together is more effective in improving lactation Performance and reducing hepatic lipid content compared with CFA or CCA addition alone.