Abstract： Objective To study the changes of the contents of serum HDL subclasses in type 2 diabetic patients. Methods The contents of serum HDL subclasses in healthy controls (n=38) and patients (n=38) were determined by two-dimensional gel electrophoresis associated with immunodetection method. Results The contents of pre-β1, HDL(P< 0.001) 、pre-β2 HDL and HDL3a (P<0.05) increased significantly and those of HDL2b (P<0. 001 ) and HDL2a (P<0.05) decreased significantly in the patients,compared with healthy controls. FBG and serum TG concentrations of the patients showed positive correlation with pre-β1, HDL (r=0.443.,r=0.697) .HDL3c (r=0.477,r=0.542) and HDL3a (r=0. 374,r =0.470) and negative correlation with HDL2b(r=-0.567,r=-0.579). Conclusion The particle size of HDL in type 2 diabetie patients showed a general shift toward smaller size, which indicated that the maturation of HDL could be abnormal in the patients.