Objective To examine plasma levels of MDA-LDL and pregnancy-associated plasma protein-A in patients with angiography type lesions Ⅱ(representing plaque rupture with or without thrombosis), and to evaluate the effect of simvastatin on plasma MDA-LDL and PAPP-A. Methods One hundred and ten patients were enrolled and underwent coronary angiography with 85 patients diagnosed as coronary heart disease (CHD) and twenty-five as controls. According to the morphologic types of plaque, the patients with CHD were straitified as type Ⅰ(smooth borders) (n=31) and type Ⅱ(irregular lesions) (n=35) and type Ⅲ (long lesions with irregular surface) group (n=19). The patients in type Ⅱ group received simvastatin (40 mg/d ) for four weeks. The plasma MDA-LDL, PAPP-A, LDL, HDL levels before and after simvastatin treatment were determined. Results Plasma levels of MDA-LDL, PAPP-A in type Ⅱ group was significantly higer than that in the controls group, type Ⅰ group, type Ⅲ group (P