The aim of this study is to optimize the extraction and purification process for anti-HSV polysaccharides from Prunella Vulgaris.Methods:The extraction method was modified by an orthogonal array experiment on three variable parameters：extraction time，solvent volume and extraction times.The content of polysaccharides and extraction yield were used as index.The effects of ultrafiltration technology and alcohol precipitation were compared in the purity of polysaccharide and anti-HSV activity.Results:The optimized extraction parameters are three extractions，1.5 hour extraction time，14 times of water for the first extraction and 12 times of water for the second and third extraction.The polysaccharide obtained from ultrafiltration technology and alcohol precipitation showed anti-HSV-1 activity in MTT assay，with IC50 values of(93.99 ± 13.12）μg/mL and(51.35 ± 15.30）μg/mL，respectively.The results suggested that the two purification processes have significantly different degrees of polysaccharide purity.The anti-HSV activity of polysaccharide from ultrafiltration technology was significantly higher than that of alcohol precipitation.Conclusion:The polysaccharides from Prunella Vulgaris obtained using ultrafiltration technology have higher anti-HSV activity than that isolated by alcohol precipitation.