This article was aimed at discussing the laws of compound medicine application of traditional Chinese medicine (TCM) in the treatment of influenza A (H1N1). Data on 4037 influenza A (H1N1) cases were collected in a multicenter cohort study using compound TCM treatment during the influenza A (H1N1) outbreak in Guangzhou from December 2009 to April 2010. The laws of TCM compound medicine application were summarized based on syndrome differentiation. The results showed that 156 kinds of Chinese herbs were used: heat-clearing and detoxifying medicinal, cough-suppressing, phlegm-relieving and panting-calming medicinal, wind-cold dispersing medicinal, wind-heat dispersing medicinal, heat-clearing and fire-purging medicinal. These medicinal occupy 51.90% in the prescription. Twenty-eight kinds of TCM medicinals were commonly used. The channel tropism involved 12 channels. The main channels were the Lung meridian, Stomach meridian, Heart meridian, and Liver meridian. The proportion of these medicinals occupies 78.71%, and all medicinals cover 7 kinds of tastes. The top three tastes are bitter, sweet, and pungent. Their proportion was 99.57%. The top 10 commonly used TCM medicinals (except for RADIX GLYCYRRHIZAE) were RADIX PLATYCODONIS, FRUCTUS FRUCTUS FORSYTHIAEE, FLOS LONICERAE, FOLIUM MORI, RHIZOMA PHRAGMITIS, HERBA MENTHAE, FLOS CHRYSANTHEMI, HERBA LOPHATHERI, FRUCTUS ARCTII, and SEMEN ARMENIACAE AMARUM. The most frequently used prescription in the group of expelling exogenous wind heat was Yin-Qiao Powder. The prescription of expelling exogenous wind cold was Jing-Fang-Bai-Du Powder. The frequency of using Ma-Xing-Shi-Gan Decoction to remove toxic heat blocking in the lungs was approximately 100%. It is concluded that the efficacy, taste, channel tropism, and compatibility of the TCM medicinals used in the treatment of H1N1 flu were closely related to the etiological factor and the pathogenesis of Influenza A (H1N1).
