Abstract: Objective To investigate the effects of medium and long chain fatty acid triacylglycerol on lipid metabolism in hypertriacylglycerolemia patients at different ages. Methods Patients with hypertriacylglycerolemia were enrolled and divided into two groups. One group received long chain fatty acid triacylglycerol oil（LCT）, and the other group received medium and long chain fatty acid triacylglycerol oil（MLCT）. All patients were asked to have fixed energy intake and physical activity daily during the whole study,and consume 25-30g of LCT and MLC oils daily for 8 weeks. Anthropometric measurement,blood biochemical variables and CT scanning at umbilical level were done at the initial and final time points of the study. Results Compared with those who received LCT oil,the body weight,BMI,WC,HC,WHR,body fat,body fat %,total fat area,visceral fat area and subcutaneous fat area were significantly decreased in patients under the age of 60 years who received MLCT oil after 8 week. No similar results were found in patients over the age of 60 years. The levels of ApoB,ApoAII,ApoC2,and ApoC3 were significantly lower in patients under the age of 60 years who received MLCT oil than in those who received LCT oil. The levels of TG,LDLC,ApoA1,ApoB,ApoAII,ApoC2,and ApoC3 at the initial and final time points were significantly lower in patients under the age of 60 years who received MLCT oil than in those who received LCT oil. However,no similar results were noted in patients over the age of 60 years. Conclusion Consumption of medium and long chain fatty acid triacylglycerol can reduce body weight,body fat and concentration of blood triacylglycerol,thus improve apolipoprotein metabolism in hypertriacylglycerolemia patients under the age of 60 years.