The effects of Pleurotus (P.) eryngii on the weight gains, food efficiency ratios, serum and hepatic lipid concentrations were investigated in male rats fed the high fat diets. Twenty one week-old Sprague-Dawley rats were given three different types of diet for 10 weeks, respectively: a control diet (high fat; $20\%$ lard), two kinds of P. eryngii diet supplemented with $3\%;or;5\%$ of dry P. eryngii powder in substitutes for the same amounts of cellulose in the control diets. The body weight gains and food efficiency ratios of the rats fed $3\%;and;5\%$ P. eryngii diets were significantly lower than those of the rats fed the control diet. The concentrations of hepatic total lipid and triglyceride in the rats fed the P. eryngii diets were significantly lower than those in the rats fed the control diet. But the hepatic cholesterol contents of the rats fed the P. eryngii diets were similar to those of the rats fed the control diet. The concentrations in serum total cholesterol, LDL-cholesterol, and atherogenic index ratios were significantly lower in the rats fed the P. eryngii diets compared to those fed the control diet. The HDL-cholesterol/total- cholesterol ratio was significantly higher in the rats fed the P. eryngii diets compared to those fed the control diet. There were no significant difference found in the serum triglyceride, phospholipid and HDL-cholesterol concentrations among the experimental groups. These results showed that feeding of P. eryngii powder feeding decreased the total cholesterol, LDL-cholesterol and atherogenic index and increased the HDL-cholesterol/total-cholesterol ratio in serum of the rats fed high fat diet.