Object To study the inhibitory effect of Anti-EB Virus Liquor (AEVL) on EB (Epstein-Barr) virus antigen expression and its cytotoxicity. Methods The effect of AEVL on Raji cell early antigen (EA) expression and B 95-8 cell virus capsid antigen (VCA) expression was assayed by indirect fluorescent technique; the cytotoxicity on nasopharyngeal carcinoma CNE 2 cells was determined by MTT method. Results At the non-toxic concentration, AEVL had markedly inhibitory effect on Raji cell EB-virus, IC 50 was 0.667 mg/mL and showed powerfully inhibitory effect on B 95-8 cell EB-virus VCA expression, IC 50 was 0.89 mg/mL; and it had strongly inhibitory effect on B 95-8 cell EB virus VCA expression stimulated by sodium n-butyric acid, IC 50 was 1.4 mg/mL. The IC 50 of AEVL on human nasopharyngeal carcinoma CNE 2 cell was 7.57 mg/mL. Conclusion AEVL could inhibit EB virus antigen expression and have cytotoxicity on nasopharyngel carcinoma cells at high concentration.