Abstract: Objective To investigate the changes and clinical significance of serum P-selectin level, high sensitivity C reactive protein (hs-CRP) and platelet in patients with coronary heart disease (CHD) and acute myocardial infarction (AMI). Methods 40 cases of AMI, 40 cases o f CHD and 40 cases of normal people were involved in this study. The levels of serum P-selectin, Hs-CRP and platelet were analyzed by ELISA. Results The levels of P-selectin in patients with AMI were higher than those CHD and normal controls. The levels of P-selectin in patients with CHD were higher than normal controls. The levels of hs-CRP in patients with AMI were higher than those CHD and normal controls. The levels of hs-CRP in patients with CHD and normal people had no significant difference. The levels of platelet in patients with AMI and CHD and normal people had no significant difference. Conclusion The P-selectin is the marker of platelet activation and may play an important role in prediction of AMI and CHD.