Abstract:High density lipoprotein(HDL)is not a homogeneous category of lipoproteins, different HDL subclasses have distinct but complementary metabolic function.Alterations in plasma lipid and apolipoprotein levels can interfere with the distribution of HDL subclasses that affect atherosclerosis risk.The general shift toward smaller size of HDL particle size in hypertriglyceridemia (HTG), hypercholesteromia (HCL) and mixed hyperlipidemia (MHL) subjects, and the changes were more prominent with the elevation of TG and TC levels which imply that HDL maturation might be abnormal and reverse cholesterol transport (RCT) pathway might be weakened, and these changes were more serious in MHL subjects.Apolipoproteins have distinct but interrelated roles in HDL particles generation and metabolism.As the concentration of apoAⅠ increases, the contents of all HDL subclasses increase significantly.The most significant association was observed between large-sized HDL2b contents and apoAⅠ.ApoAⅡ played a dual function in the contents of HDL subclasses, and both small-sized HDL3b and HDL3a and large-sized HDL2b tended to increase with apoAⅡ concentration.Plasma apoB-100, apoCⅡ, and apoCⅢ appear to play a coordinated role in assembly of HDL particles and the determination of their contents.Higher concentrations of apoAⅠ could inhibit the reduction in content of large-sized HDL2b affected by apoB-100, CⅡ, and CⅢ.The particle size of HDL tend to be small in diabetes and CHD patients.For CHD patients with statins therapy, the HDL subclasses phenotype modification lagged behind the improvement of plasma lipids levels.The HDL subclasses distribution may help in severity of coronary artery and risk stratification, especially in CHD pa-tients with therapeutic low density lipoprotein (LDL), triglyceride(TG) and HDL levels.