Objective: To observe effect of Qiwei Qingyan aerosol for treatment and prevention and H1N1 virus as well as the efficacy when combining with tamiflu. Method: The method of cell and tissue culture was utilized to carry out an observation on the cytopathy effect(CPE) led by influenza virus FM1 with the aerosol of different concentrations in vitro. The swing influenza A(H1N1)virus FM1 was adopted to establish pneumonia model in mice by nasal dropping method to detect the efficacy of the aerosol for treatment in vivo. In addition

Combining the aerosol with tamiflu (both in 50% dose) to inspect the efficacy for efficiency improvement and toxicity depression of Chinese traditional medicine. Result : ①The maximal nontoxic concentration (TC0) of Qiwei Qingyan aerosol was 0.192 g ·L-1 to Hela and Hep-2 cell. Within this concentration range it could relieve CPE induced by influenza virus

which was comparatively weak.②After 7-days successive high-dose medication of Qiwei Qingyan aerosol

the TNF-α level in serum of mice infected by H1N1 virus could be decreased apparently. Meanwhile

the IL-2 level could be increased significantly.③A combination of half dose tamiflu and moderate dose aerosol lowered the lung index of infected mice. As well

a lesser extent of lung tissue lesion was discovered 4.The ability of the combination to decrease the neuraminidase(NA) activity in the blood of the infected animals was superior to tamiflu solely used. Conclusion : By affecting the function of mice's immune system

Qiwei Qingyan aerosol improved the pneumonia symptoms induced by influenza virus and decreased the lung index of H1N1 infected mice. Furthermore

the combination with tamiflu possessed the effect of improving the efficiency and depressing the toxicity.