Abstract: OBJECTIVE To study the antiviral effects of emodin on human cytomegalovirus and to explore the molecular mechanism through observation the effect of emodin on HCMV and viral gene transcription. METHODS MRC5 cell viability and HCMV inhibitory rate of emodin and ganciclovir in different dosage groups were detected with MTT method.ALL data were input to IBM SPSS STATISTICS 22.0 software for analyzing 50% toxic concentrations(TC50), 50% inhibition concentration(IC50) and therapeutic index(TI).HCMV AD169 weve established strain infected cells as the virus control group, emodin intervention infection cell model for emodin group and ganciclovir group,real-time fluorescent quantitative PCR method was wsed to detect virus immediate early genes ul122 mRNA, early genes ul54 mRNA, late genes ul83 mRNA dynamic expression of three groups after infection for 0.5h,2 hours and 24hours.RESULTS The TC50 of emodin and ganciclovir were 75.96μg/ml and 167.43 ug/ml; the IC50 were 7.31μg/ml and 26.50μg/ml;TI were 10.39 and 6.31μg/ml. 2 In different time of virus infection, ul122 and ul54 mRNA expression of emodin group were lower than virus control group and ganciclovir group. 24h after virus infection, ul83 mRNA expression of emodin group were lower than virus control group and ganciclovir group.CONCLUSION Therapeutic index of emodin is superior to ganciclovir, therefore emodin possesses HT5"SS a better application prospect on inhibiting human cytomegalovirus. In cellular level emodin can significantly inhibit HCMV AD169 strain of immediate early, early gene, late gene transcription level, show that emodin early intervention of HCMV virus gene is the main link of antiviral.