Abstract: Objective：〖WT5”BZ〗To investigate the antiviral effects of the water and alcohol extracts of Dryopteris Crassirhizoma.〖WT5”HZ〗Methods：〖WT5”BZ〗（1）The cytopathic method was used to observe the antiviral effects in vitro of the water and alcohol extracts of Dryopteris Crassirhizoma on influenza virus(FM1),respiratory syncyntial virus(Long),para influenza virus(Ⅰ,Ⅲ),adenovirus(AD3);(2)Mice were randomly divided into treated group(25%,12.5%,6.25% extract as high,middle and low dose respectively),normal control group and model group,the in vivo antiviral effects of them were studied in mice infected with influenza virus(FM1) on induced lung index.〖WT5”HZ〗Results：〖WT5”BZ〗〖JP2〗Both the water and alcohol extracts of Dryopteris Crassirhizoma had the antiviral effect on influenza virus(FM1),respiratory syncyntial virus(Long),para influenza virus(Ⅰ,Ⅲ),adenovirus(AD3).EC50 of the water extract was 110.58，141.72，126.21，152.66 and 182.55 ng/L,TI was 34.94，14.21，30.62，25.31 and 21.17.〖JP〗EC50 of the alcohol extract was 152.08，168.27，132.28，135.26 and 156.38 ng/L,TI was 14.24，11.12，16.37，16.01 and 13.84.The water extract 250 mg/L（P＜0.01）125 mg/L（P＜0.05）,the alcohol extract 250 mg/L（P＜0.01）Significantly inhibited lung index of mice infected with influenza virus(FM1) increased the injury caused by virus.〖WT5”HZ〗Conclusions：〖WT5”BZ〗The water and alcohol extracts of Dryopteris Crassirhizoma have the antiviral effect，which can reduce the lung injury caused by virus.

Key words: Dryopteris Crassirhizoma/separation and purification;Influenza virus/action of drugs, Respiratory syncyntial virus/action of drugs;Adenovirus/action of drugs;Animal,experiment