Objective:To observe and discuss the effects of Xuebijing injection on the expression of P-selectin in serum and on the pulmonary vascular endothelial cells of PTE model rats. Methods:The PTE model was established by intravenous injection of autologous blood clots. One hundred and five healthy male SD rats were randomly divided into control group,PTE model group,and Xuebijing-treated group. Every group were divided into 5 subgroups according to the time of 1 hour,3 hour,1 day,3 day and 7 day after opreation,with 7 rats in each subgroup. Pathological changes of lung tissue were observed,and the expression of P-selectin protein on the pulmonary vascular endothelial cells was evaluated by Western blot. The contents of sP-selectin in serum were detected by ELISA. Results:The notable embolism in pulmonary arteries and inflammatory cell infiltration around alveoli could be found by microscopy. The expression of P-selectin protein on the pulmonary vascular endothelial cell and the contents of P-selectin in serum significantly elevated from 1 hour after embolization (P < 0.01). Whereas after using Xuebijing injection,the pathological injury was ameliorated.The expression of Ps protein on the pulmonary vascular endothelial cells were significantly decreased from 1 hour after embolization (P < 0.01). The contents of P-selectin in serum were also decreased and the differences between PTE model group and Xuebijing-treated group were statistically significant from 1 day after embolization(P < 0.01 or P < 0.05). Conclusion:Xuebijing injection may reduce the damage of inflammation and coagulation-fibrinolysis imbalance to the lung tissue through decreasing the expression of P-selectin in PTE,so it has a certain protective effect to the lung tissue.