This study was attempted to investigate the effect of Tricholoma matsutake on experimentally induced hyperlipemia in rats. The levels of cholesterol, triglyceride and phospholipid were measured. Diagnostic attention has been paid to the cholesterol concentration associated with high density lipoprotein (HDL), which appears to be inversely related to the incidence of coronary artery disease. For these reasons, determination of HDL-cholesterol has significant meaning. Total cholesterol was determined by Abell-Kindall method, and to measure HDL-cholesterol, serum low density lipoproteins (LDL) were first selectively precipitated by HDL-precipitating reagent. The results obtained were as follows : 1) The level of total cholesterol in serum of hyperlipemic rats was decreased by oral administration of Tricholoma matsutake extract. 2) The level of HDL-cholesterol was increased by the mushroom extract. 3) The level of triglyceride was significantly decreased by the mushroom extract. 4) The level of phospholipid was slightly decreased by the mushroom extract.