Abstract: Objective: To investigated the relationship between serum C-reactive protein (CRP)and macroangiopathy of type 2 diabetes millitus,and the mechanism of Simvastatin in protection of blood vessels.Methods: Sixty-nine cases of type 2 diabetes mellitus were selected,34 of whom had only type 2 diabetes with no complications(group A) and 35 of whom were accompanied by macroangiopathy(group B),and 20 healthy subjects acted as controls(group C).The serum CRP was determined by immuno-turbidimetric.The changes were observed before and after simvastatin treatment.Results: The serum CRP in group A and B were higher than that in group C(P<0.05 and P<0.01),while group B had higher serum CRP levels than group A(P<0.01).Serum CRP had a positive correlation with TC,C-LDL,ox-LDL,SBP,BMI(P<0.05 to P<0.01),and had a negative correlation with C-HDL(P<0.01).After simvastatin treatment,the levels of serum CRP,TC,C-LDL,ox-LDL reduced remarkably(P<0.01).Conclusions: Serum CRP may play an important role in the development and progression of type 2 diabetic macroangiopathy.Simvastation protects the blood vessel by its mechanism of anti-inflammation,anti-oxidation and moderating lipid.