We have determined the trace element composition of anti-influenza virus mushrooms using atomic absorption spectrophotometer. The elements present in greater concentration in Ganoderma lucidum samples are selenium, iron, and zinc, with selenium being the element with the highest concentration of all, at 416 ± 38.5 mg/kg; in Cordyceps militaris samples are iron, selenium, and zinc, with iron being the element with the highest concentration of all, at 291 ± 20.9 mg/kg; in Kuehneromyces mutabilis samples are selenium, iron, and manganese, with selenium being the element with the highest concentration of all, at 203 ± 9.8 mg/kg; in Inonotus hispidus samples are zinc, selenium, and iron, with zinc being the element with the highest concentration of all, at 194 ± 16.9mg/kg; in the Collybia maculata samples are iron, selenium, and zinc, with iron being the element with the highest concentration of all, at 274 ± 22.2 mg/kg, respectively. The average metal concentrations in mushrooms decreases in the order: selenium > iron > zinc > chromium > manganese > copper > magnesium > lead. After the mice were administered (orally) with mushroom extracts for 8 weeks and inoculated intranasally with viral suspension, element levels in serum were also measured. Highly significantly increased values of Se, Zn, and Mg in the serum of mice supplemented with anti-influenza virus mushrooms were a characteristic finding. Se, Zn, and Mg present in mushrooms may play a direct or indirect role in their anti-influenza virus nature. They may provide prophylactic protection against influenza infection via stimulation of host innate immune response.