This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of Chinese medicinal herbs for treating people of all ages with established diagnosis of influenza. We are also interested in comparing the effects of various Chinese medicinal herbs for treating influenza with each other and any adverse events. In comparisons between groups intended for treatment with Chinese medicinal herbs and groups allocated to the placebo or other current treatment regimes, or various Chinese medicinal herbs, the following hypotheses will be tested: (1) There is no difference in the number of people cured at the end of the third day. (2) There is no difference between various Chinese medicinal herbs in the treatment of influenza (3) There is no difference in the number of adverse events.