1. This study investigated the effects of supplementary dietary L-carnitine on the performance, serum components, carcase traits and specific activities of hepatic enzymes related to beta -oxidation of fatty acids in broiler chickens. One hundred and eighty 1-d-old broilers were divided into 2 groups, each with 3 replicates, and given diets supplemented with 0 and 160 mg L-carnitine/kg for 6 weeks. 2. Experimental results indicated that supplementary carnitine did not significantly influence the performance and carcase characteristics of the broilers. 3. The serum triacylglycerol (TG) and nonesterified fatty acid (NEFA) concentrations in the carnitine supplemented group were significantly lower than that in the control group (P<0.05). However, the effect on serum cholesterol, phospholipids concentrations and lipoprotein profiles were not significant (P>0.05). 4. Carnitine palmitoyl transferase activity in the carnitine-supplemented group was significantly (P<0.05) higher than in the control; however, carnitine supplementation did not significantly affect the activities of other fatty acid <beta>-oxidation enzymes. 5. The results in this study demonstrated that supplementary carnitine facilitated fatty acid transportation and did not influence the performance or carcase characteristics of broilers.