Objective: To observe the effects of Astragalus Polysaccharide (APS) on activity and morphological Changes in human umbilical vein endothelial cells (HUVEC) induced by serum from patients with blood stasis syndrome (BSS) and hypertension. Method: The HUVEC was affected by the serum of the patient with BSS associated with hypertension and different dosage of APS was applied for intervention.The activity of the HUVEC was determined by MTT assay and the morphological changes were observed by the inverse phase contrast microscope. Result: APS had the protective effect for lightening the HUVEC shape change affected by the serum from patient of BSS associated with hypertension and the activity was increased in a dose-dependent manner. Conclusion: APS can lighten the injury of the HUVEC affected by the serum from the patient of BSS associated with hypertension

increase cells activity and maintenance for the normal shape of the cells.