Objective To explore the relationship between C-reactive protein and pathological changes of coronary artery.Methods One hundred and fifty-three patients who had no myocardial infarction,cardiac failure,injury,infection and cancer etc,and were approved by CAG were selected.The patients were retrospected in this study.Forty-three cases of the control group were normal coronary artery,39 cases with single vessel pathological changes,32 cases double vessel pathological changes,and 39 cases three vessel pathological changes,which were defined as single,double and three group respectively.The levels serum CRP of all patients were detected within 24 hours. Results There were significant differences among four groups. CRP levels of coronary heart disease were higher than that of control group.Serum CRP levels in three vessel pathological changes were higher than double vessel pathological changes and much higher than single vessel pathological changes. Conclusion Levels of serum CRP is correlated with pathological degree of coronary artery.