With　the　application　of　the　immune　enzyme　assay,　the　inhibitory　effects　of　herbal　polysaccharides　on　the　transcriptional　activation　of　Epstein-Barr　virus　(EBV)　early　antigen　in　the　Raji　cell　have　been　researched.　The　test　result　shows　that　Astragalus　polysaccharide　(APS),　Ganoderma　lucidum　polysaccharide　(GLP)　and　Epimedium　polysaccharide　(EPS)　have　inhibitory　effects　in　certain　range　of　dose.　APS　and　GLP　have　significantly　better　inhibitory　effects　than　EPS.　In　addition　these　polysaccharides　and　their　inhibitory　effects　on　EBV　antigen　expression　have　dose-effect　relationships.　In　conclusion,　this　method　can　be　used　for　finding　new　anti-EBV　drugs　in　natural　medicine.　New　anti-EBV　drugs　will　inhibit　EBV　antigen　expression　and　prevent　cell　carcinogenesis,　so　that　they　will　be　used　for　prevention　and　treatment　of　EBV　associated　disease.　Furthermore　the　experiment　reveals　a　new　mechanism　of　herbal　polysaccharides＇　anti-virus　and　anti-tumor　effects.