Abstract: Objective To observe the effect of edible oil containing medium-chain fatty acid（MCFA） on blood lipid metabolism in patients with hypertrigliceridemia complicated with different HDL-C levels. Methods One hundred and twelve patients with hypertriglyceridemia were randomly divided into MCFA group and long-chain fat acid（LCFA）group according to their initial HDL-C levels（＜1.04mmol/L,=1.04-1.54mmol/L,and ≥ 1.55mmol/L）.Their daily intake of food and edible oil（25-30g/d）,and physical activity time were controlled.Their fasting biochemical indexes including TC,TG,HDL-C,LDL-C,ApoA1,ApoB,ApoA2,ApoC2,ApoC3 and ApoE levels were measured before beginning and 8 weeks after study with the double blind control method. Results Efficient data were obtained from 101 patients（50 in LCFA group and 51 in MCFA group）.No significant difference was observed in gender,daily nutrient intake,and physical activity time between the two groups（P＞0.05）.The TG,LDL-C,and ApoB levels were significantly lower while the HDL-C,HDL-C/LDL-C,（ApoA1+ApoA2）/ ApoB levels were significantly higher in MCFA group with a low HDL-C level than in LCFA group（P＜0.05）.No significant difference was observed in all indexes of MCFA group with a high HDL-C level（P＞0.05）. Conclusion Rational intake of MCFA can reduce the blood TG level in those with a low HDL-C level and improve their lipoprotein and apolipoprotein levels in patients with hypertrigliceridemia.