The present invention relates to use of a composition in the manufacture of a health care product or medicament for preventing and treating leucopenia induced by radiotherapy or chemotherapy. The composition is made from raw materials comprising 5 to 200 parts by weight of Ganoderma, 5 to 150 parts by weight of Radix Panacis Quinquefolii or Radix Et Rhizoma Ginseng, 1 to 90 parts by weight of fermented Cordyceps sinensis powder and/or 1 to 120 parts by weight of Cordyceps, or is a composition consisting of water and/or alcohol extracts of the above raw materials as active components.
