The material basis of Cordyceps sinensis (Berk.) Sacc has not yet been well understood and natural C. sinensis resources are very rare. The present study aimed to clarify the substance basis and compare the protective effect of natural and artificially-cultivated C. sinensis against cyclophosphamide (CTX)-induced myelosuppression. Both natural and artificially-cultivated C. sinensis effectively improved CTX-induced decrease of peripheral blood counts and hemopoietic growth factors, pathological changes, and apoptosis of bone marrow. Importantly, artificially-cultivated C. sinensis...