This experiment was conducted to study the effects of supplementing and withdrawing enramycin on growth performance, activity of digestive enzyme, intestinal morphology and expression of sodium-glucose transporter 1 (SGLT 1) mRNA and peptide transporter 1 (PepT 1) mRNA in weanling piglets. Twenty PIC weanling piglets at 21-old-day with similar weight and gender were randomly allocated to 4 dietary treatments with 5 replicates in each treatment of 1 piglet of per replicate. The piglets were fed a basal diet supplemented with enramycin at 0, 5, 20, and 80 mg/kg for 4 weeks, respectively. At the 5th week, enramycin was withdrawed and all piglets in 4 treatments were received basal diet for 1 week. In the morning on day 36, all piglets were given intraperitoneal injection of LPS at 200 mg/kg body weight, and after 3 days of injection, piglets were slaughtered to determine activities of digestive enzyme, intestinal morphology and expression of sodium-glucose SGLT 1 mRNA and PepT 1 mRNA. Results showed that during the first 4 weeks, ADG in treatment 1 and treatment 2 tended to be improved, and ADG in treatment 3 significantly lower than that in treatment 1 and treatment 2 (P<0.05). But at 5th week, ADG and ADFI in all treatments were no significant difference (P>0.05). With supplemented with enramycin for 4 weeks then withdrawed for 1 week in diet of piglets, the activities of lipase, amylase and trypsin in jejunum were significantly depressed (P<0.05), and the ratio of the villus height to the crypt depth of duodenum were significantly increased (P<0.05), and expression of SGLT 1 mRNA and PepT1 mRNA was also significantly increased (P<0.05). In conclusion, supplementation with enramycin of 5～20 mg/kg in diet could improve growth of piglets; withdrawing enramycin could decrease activities of digestive enzyme, and damage structure of intestinal mucosa, and depress the function of digestion and resorption in piglets.［Chinese Journal of Animal Nutrition, 2010，22（1）:139-144］