Objective To explore the possible mechanism of the formation of blood stasis syndrome in coronary heart disease unstable angina pectoris. Methods One hundred and ten patients with coronary heart disease unstable angina pectoris were selected

with 60 cases of blood stasis syndrome and 50 cases of non blood stasis syndrome.Patients’ peripheral blood platelet microparticle and the expressions of the surface membrane protein P-Selectin

platelet activating complex 1（ PAC-1）

platelet membrane glycoprotein Ibα（ CD42b） and CD40 L in both groups were detected. The correlation of these indexes and coronary heart disease blood stasis syndrome was analyzed. Results In patients with coronary heart disease unstable angina pectoris

peripheral blood platelet microparticle and the expression levels of the surface P-Selectin

PAC-1 and CD40 L of those with blood stasis syndrome were higher than those of patients without blood stasis syndrome（ P < 0. 05）

which were positively correlated with blood stasis syndrome（ P <0. 05）

with r values of 0. 427

0. 294

0. 200 and 0. 218

respectively. Conclusion The formation of blood stasis syndrome in patients with coronary heart disease unstable angina pectoris of might relate to the effect of adhesion

aggregation and inflammatory response of platelet microparticle.