This experiment was conducted to investigate the effects of feeding levels of milk replacer on growth, body weight gain, digestion and absorption of nutrients, and serum biochemical indices in calves. Twenty four new-born calves with similar body weight were allotted into 3 treatments with 8 replicates each and 1 calf in each replicate. The calves were raised in single cages. Each treatment was fed milk replacer at a level of 1.188% (group L), 1.375% (group M) or 1.563% (group H) of the body weight. Body weight was measured and blood samples were collected at 0, 2, 4, 6 and 8 weeks of age. The metabolism trials were conducted during 3 to 4 and 5 to 6 weeks of age, respectively. The weekly weight gain of calves from either group M or H were significantly higher than that of group L (P<0.05) during 3 to 4 weeks of age, but it did not significantly differ among the 3 groups (P>0.05) in other stages, and the feeding levels of milk replacer had a positive effect on body weight. During 3 to 4 weeks of age, the digestibility of dry matter and organic matter was significantly higher in calves from group L than those from group H (P<0.05), and the digestibility of crude protein was significantly higher in calves from group M than those from group H (P<0.05), but the digestibility of ether extracts, calcium and total phosphorus was not significantly differ among the 3 groups (P>0.05). During 5 to 6 weeks of age, the digestibility of dry matter, organic matter and calcium was significantly higher in calves from group M than those from group H (P<0.05), but that of crude protein, ether extracts and total phosphorus was not significantly differ among the 3 groups (P>0.05). The serum biochemical indices were influenced by the weeks of age, and the feeding level did not differ among the 3 groups (P>0.05). At 2 weeks of age, the concentration of serum albumin was significantly higher in calves from either group L or group M than those from group H (P<0.05), the concentration of serum triglyceride in group H was significantly higher than that in group L (P<0.05), and the serum urea nitrogen concentration in group M was significantly higher than that in group L (P<0.05). The results indicate that milk replacer has effects of varying degrees on the body weight gain, digestion and metabolism of nutrients, and serum biochemical indices in calves. It is feasible for calves when milk replacer is fed at a level of 1.375% of the body weight.［Chinese Journal of Animal Nutrition，2011，23（4）：654 -661］