This experiment was conducted to investigate the effects of choline supplemental level on lipid metabolism in liver of 3-to 5-month-old Rex rabbits. Two hundred 3-month-old Rex rabbits with similar body weight were randomly divided into 5 groups with 40 replicates in each group and 1 rabbit in each replicate. Rabbits in the 5 groups were fed experimental diets which supplemented with 0 (control), 200, 400, 600 and 800 mg/kg 50% choline chloride (converted from 50% choline chloride to choline, the supplemental levels were 0, 87, 174, 261 and 348 mg/kg, respectively) based on a basal diet, and the measured levels of choline in experimental diets were 812, 902, 993, 1 086 and 1 170 mg/kg, respectively. The pre-test period lasted for 7 days, and the experimental period lasted for 53 days. The results showed that dietary choline supplemental level had significant effects on the contents of monounsaturated fatty acids and polyunsaturated fatty acids in liver (P<0.05). Compared with control group, dietary supplemented with 87, 174, 261 and 348 mg/kg choline significantly increased the contents of insulin-like growth factor 1 (IGF-1) and leptin (LEP) in serum (P<0.05), dietary supplemented with 174 and 261 mg/kg choline significantly increased the content of growth hormone (GH) in serum (P<0.05), dietary supplemented with 261 and 348 mg/kg choline significantly increased the lipoprotein lipase (LPL) activity and very low density lipoprotein (VLDL) content in serum (P<0.05), and dietary supplemented with 261 mg/kg choline significantly increased the carnitine palmitoyltransferase-1 (CPT1) mRNA expression level in liver (P<0.05). In conclusion, dietary supplemented with 261 mg/kg choline (the measured level of choline in the diet is 1 086 mg/kg) alters the fatty acid composition in liver, promotes the CPT1 gene expression, which is the key enzyme fatty acid oxidation, strengthens the output process of triglycerides (TG) from liver.