In this paper, radiation decontamination effects of mycelium powder of sinensis with ,60,Co γ-rays and influence on its components were studied. The results showed that the irradiation was very effective in killing bacteria and moulds in mycelium powder. The ,D,10, value for bacteria and moulds were 5.51kGy and 5.72kGy respectively. The optimum dose for decontamination of mycelium powder was 8—9kGy. Irradiating the mycelium powder to 8—9kGy did not cause obvious changes in the content of fatty acid, protein, total polysaccharide, total free amino acid and major nutrient components of adenosine, mannitol, and nitrogen. The irradiated mycelium powder, lost respectively 8.4%—9.5% and 29.6%—33.3% vitamin C and E, but they are minor nutrient components. After radiation decontamination, the quality-guaranteed mycelium powder has extended shelf life.