14 Japanese patients ≥18 years old who were diagnosed to have influenza A by an influenza antigen detection kit test were randomized to two groups and received either Maoto and Shosaikoto (MS; n=6) or Oseltamivir (O; n=8). The MS group received 7.5 g/day Maoto extract granules and the same dose of Shosaikoto for 3 days. The O group received 150 mg/day Oseltamivir for 5 days. No significant differences were observed between the MS and the O group in regards to the duration of fever after treatment (2.3±1.0 vs. 2.0±0.6 days).