The purpous of the study was to find an effect of oral administered medium chain triglyceride(MCT) diet on the serum and enzyme activities of Spraque-Dawly rats when they were oral fed with MCT, soybean oil and palm oil. The result was as follow. 1) The body weight gains in MCT diet group was lower than that of the all experimental group. 2) Total cholesterol levels in serum and liver of MCT diet group were very lower than that of the all experimental groups. 3) HDL-cholesterol level of MCT diet group was higher than that of the all experimental group except normal group and VLDL, LDL-cholesterol levels was very higher. 4) TG and PL levels of MCT diet group higher than that of the control group. 5) The activities of GOT with soybean oil diet group and of GPT with MCT diet group were lower than that of the all experimental group. 6) HDL-levels in the serum lipoprotein of MCT diet group was increased and LDL levels was decreased.