Black fungus is a nutritional nutritious food, highquality black fungus black smooth, its back slightly offwhite, easily physique, body dry flesh, flowershaped neat, shiny surface, ear lobe stretch, flower piece and flexible in the olfactory fragrance of the gas. Grade one: ear piece dark brown, shiny feeling, back gray; allowed to have boxing ears, flow ears, loss of ear, ear worms and rotten ears; duo pieces intact, not by 2cm in diameter sieve; moisture content of not more than 14 %; wet ratio of 1:15 or more; ear thickness 1mm or more; impurities must not exceed 0.3%. Grade two: the ear piece dark brown, dark gray back; allowed to have boxing ears, flow ears, loss of ears, ears and mildew infestation ear; duo pieces intact, not by 2cm in diameter sieve; moisture content does not exceed 14%; wet ratio of 1:14 or more; ear thickness of 0.7mm or more, the impurities should not exceed 0.5%. Grade three: the ear pieces, mostly glossy dark brown or light brown; boxing the ears of not more than 1%; flow ear does not exceed 0.5%; does not allow the loss of ears, ears and mildew infestation ear; small flowers or pieces, not by diameter 0.4cm of the mesh; moisture content not exceeding 14%; wet ratio of 1:12 or more; impurity less than 1%. Food value of black fungus: 1. Affect the blood system. 2. Promote immune function. 3. Affect biosynthesis. 4. Reduce atherosclerosis. 5 Antiaging effects. 6 Inflammatory antiradiation. 7. Antiulcer effect. 8 Hypoglycemic effect. 9 Cancer, anti-mutagenic. 10. Antibacterial effect. 11. Clear toxic heat the blood. 12. Eliminate spots. 13. Intestinal Qingwei polyester radiation.