The aim of this study was to investigate the effects of L-carnitine on the components of serum and liver and the effects on the anti-oxidant system. For this purpose, five experimental groups were setup. For fat source, perilla oil enough with unsaturated fatty acid and beeftallow enough with saturated fatty acid were supplemented together with L-carnitine to the rats. Five experimental groups kept eight Sprague-Dawley rats respectively, They were co group supplemented with basic diet or AIN-93, PO group supplemented with perilla oil, POC group supplemented with perilla oil and L-carnitine, BT group supplemented with beeftallow, and BTC group supplemented with beeftallow and L- carnitine. The results are. 1) Weight gain, food intake and FER were not different significantly among the experimental groups. 2) Significant difference was observed in serum total lipid(P<0.05), serum triglyceride(P<0.05), serum total cholesterol (P<0.05)and serum LDL cholesterol(P<0.05). Serum total lipid and serum triglyceride were significantly low in the groups supplemented with L-carnitine. Serum total cholesterol showed difference with the supplementation of L-carnitine in BTC only. LDL cholesterol showed no significant difference with the supplementation of L-carnatine, but total values of LDL-cholesterol were high in groups supplemented with beeftallow. 3) Total cholesterol in liver was low in POC group with the supplementation of L-carnitine however, there was no difference in BTC group with the supplementation of L-carnitine. In summary, dietary L-carnitine did not influence the weight gain, food intake and food efficiency ratio among the experimental groups, but had an effect of lowering the serum total lipid and triglyceride significantly in both groups which were supplemented with L-carnitine. The effect of lowering of sew total cholesterol with the supplementation of L-carnitine in beeftallow group(BTC) only. The effect of lowering of liver total cholesterol with the supplementation of L-carnitine in perilla oil group(POC) only.