This research was performed to investigate the effect of Codonopsis lanceolata water extracted on the levels of lipid in serum and liver of rats fed high fat diet for 6 weeks. Experimental groups were divided into normal group(NF), high fat diet group(HF), high fat diet and Codonopsis lanceolata water extract treated group(HFW). Codonopsis lanceolata water extract was orally administrated at the level of 0.1ml/100g body weight per day. Body weight gain and feed intake were not significantly different in three groups, but feed efficiency ratio was increased in HF and HFW. The weights of liver, kidney, heart were not significantly different among the groups. The level of serum total lipid was higher in HF than NF, but Codonopsis lanceolata water extract decreased the level of the lipid. The levels of serum triglyceride and total cholesterol were significantly increased in HF, but they were significantly decreased by administration of Codonopsis lanceolata water extract. The levels of serum HDL-cholesterol and phospholipid were slightly increased by Codonopsis lanceolata water extract. Codonopsis lanceolata water extract significantly decreased the levels of liver total lipid, triglyceride and total cholesterol which were increased by high fat diet.