The current study examined the effects of catechin on lipid composition of serum and liver and adipocyte of epididymal fat pads in obese rats fed high fat diet. Sprague-Dawley male rats weighing $100{pm}10g$ were randomly divided into eight groups, four normal diet groups and four high fat diet groups according to the level of dietary catechin supplement. The rats were fed ad libitum experimental diets for 4 weeks and then they were sacrificed. Body weight in HF group was heavier than that of NC group, but HFCM and HFCH groups were significantly reduced compared to HF group. Relative body weight to abdominal weight and relative body weight to epididymal weight in HF group were increased to 103% and 106%, respectively, compared to NC group, but HFCM and HFCH groups were significantly reduced as compared to HF group. The levels of serum triglyceride, total cholesterol, LDL-cholesterol and atherogenic index in HFCH groups were significantly lower than those of HF group, whereas HDL-cholesterol levels were increased. Total lipid contents of liver in HF group was significantly higher than that of NC group, but HFCH group maintained the NC level. There were no significant difference in hepatic triglyceride contents of high fat diet groups. Contents of hepatic cholesterol in HF group was 29% higher than that of NC group, but HFCM and HFCH groups were significantly reduced as compared to HF group. Cell number and cell size of epididymal fat pads in HFCM and HFCH groups were significantly reduced, respectively, compared to HF group. Improved lipid metabolism observed in rats fed catechin may be caused by an alteration of number and size in epididymal fat pad and lipid composition.