The objective of this study was to investigate the effects of the feeding Cordyceps militaris extract on the improvement of the free fatty acid, lipid peroxide, creatinine and enzyme (creatine phosphokinase; CPK, lactate dehydrogenase; LDH, alkaline phosphatase; ALP, lecithin cholesterol acyltransferase; LCAT) activities in the sera of dietary hypercholesterolemic rats (SD strain, male) fed the experimental diets for 5 weeks. Concentrations of free fatty acid, lipid peroxide and CPK, LDH, ALP activities in sera were fairly reduced in the Cordyceps militaris extract administration group (CHE) than in the hypercholesterolemic diet group (CHD). However, no significance was found in the effect of an creatinine concentration among the groups. The LCAT activity in serum was increased in the Cordyceps militaris extract administration (CHE) than in the hypercholesterolemic diet group (CHD). From these results, Cordyceps militaris extracts were effective on the improvement of the lipid components and metabolic enzyme activities in sera of dietary hypercholesterolemic rats.