Abstract: Objective To assess the clinic value of Meyer method of pulmonary perfusion imaging in evaluation of the therapeutic effect of pulmonary embolism.Methods Thirty patients who were diagnosed as pulmonary embolism and received anticoagulant or thrombolytic therapy.All patients received pulmonary ventilation/perfusion imaging before treatment within 1 to 2 days and received pulmonary perfusion imaging again after treatment within 1 to 2 weeks.The two images obtained in each patient were scored together.Meyer method of semi-quantitative visual evaluations were used.Results Thirty patients after therapy,among 15 patients obviously improve of pulmonary peffusion,8 patients lightly improve,5 patients no change and 2 patients aggravation.By Meyer method,the 23 patients of improvement group,the score of before treatment(0.45±0.14),the score of after treatment(0.22±0.11),the score was significant ehange(t=11.627,P<0.05).the 7 patients of no change group,the score of before treatment(0.23±0.15),the score of after treatment(0.23±0.17),the score was not signifieant change(t=0.143,P>0.05).the improvement rate of two groups were significant change(t=2.410,P<0.05).Conclusion The Meyer method could effectively evaluate the pulmonary perfusion change after the treatment of pulmonary embolism,and there was clinic value in evaluation of the therapeutic effect of pulmonary embolism.