We analysed the lipid and apolipoprotein (apo) composition of plasma VLDL, LDL and HDL including TG, FC, CE, PL and apoA I, A II, B100, C II, C III and E in 20 endogenous HTG patients whose plasma TG levels were > 2.26 mmol/L, TC < 6.74 mmol/L and in 20 normal subjects whose plasma lipid levels were normal (TG < 1.70 mmol/L, TC < 5.96 mmol/L). The results showed that the fasting plasma TG, apoC II, C III and E levels were significantly higher and HDL-C and apo A I levels lower in the HTG group than those in the normal group (P < 0.05). Abnormality of lipid and apolipoprotein composition of plasma VLDL, LDL and HDL in HTG was found. TG, FC, CE, PL and apoB100, C II, C III and E contents in VLDL were significantly increased in HTG (P < 0.01), while CE, apoA I, C II, C III and E in HDL were significantly decreased (P < 0.05) and TG in HDL significantly increased (P < 0.05) in HTG. TG and apoB100 in LDL in the HTG group were higher than those in the normal group (P < 0.05).