OBJECTIVE： To observe the antiviral effects of Qingre jiedu soft capsule （ADSC） against influenza A H1N1 virus in vivo， and to provide a experimental support for clinical therapy of influenza A H1N1 virus. METHODS： BALB/c mice were randomly divided into normal control group，model control group， positive drug high-dose， medium-dose and low-dose groups [oseltamivir phosphate capsule， 0.04， 0.02， 0.01 g/（kg·d）] and ADSC high-dose， medium-dose and low-dose groups [1.5， 0.75， 0.375  g/（kg·d）].Except for normal control group， others groups were given influenza A H1N1 virus with titer 1.6×10－5.2 via nasal cavity to induce poisoned mice model； 6-8 h after modeling， they were given relevant medicine intragastrically， once a day， for 5 days. After medication， the change of body weight within 7 d were observed in mice； the mortality and death prevention rate within 15 d， mean survival days （MSDs） were calculated in mice.Other mice were selected and grouped， and they were given same drugs as above. 8 h after last medication， lung index and inhibition rate of lung index were determined in mice.RESULTS： In model control group， the body weight of mice decreased significantly since 5th day， and mice death was beginning to occur since 8th day （mortality of 85.7％ within 15 d）； the lung index was increased significantly compared to normal control group （P＜0.01）. Both ADSC and oseltamivir phosphate capsule could slow down the decrease of body weight in mice， decreased the mortality and lung index of mice， and prolonged MSDs； the MSDs of mice in ADSC high-dose，positive drug high-dose and medium-dose groups were significantly higher than model control group （P＜0.05）， and lung index was significantly lower than model control group except that of ADSC low-dose group （P＜0.05）. CONCLUSIONS： ADSC has certain antiviral effect against influenza A H1N1 virus in vivo.