Effects of leucocyanidins on the level of serum lipids and lipid peroxidation was investigated in 2,3,7,8-tetrachlorodibenzo-p-dioxine(TCDD)-induced rat that were pretreated with leucocyanidins for 4 weeks. The rats were divided into five experimental groups that is leucocyanidins and low TCDD treated group(LTL, 0.1 ${mu};g/kg$ TCDD), leucocyanidins treated high TCDD group(LTH, 10 ${mu};g/kg$ TCDD), No leucocyanidins and low TCDD treated group(NTL, 0.1 ${mu};g/kg$ TCDD) and no leucocyanidins and high TCDD treated group(NTL, 10 ${mu};g/kg$ TCDD). Serum total cholesterol, LDL-cholesterol and triglyceride level were significantly decreased and HDL-cholesterol level significantly increased in leucocyanidins treated group. Serum MDA level was also significantly reduced in leucocyanidins treated group. These results suggest that pre-supplement of leucocyanidins prevented the degree of lipid peroxidation on TCDD induced rat.