Abstract: The nutritional compositon and contents of Polyporus ellisii in Yunnan were detected,and nutritional value of protein was evaluated.The results showed that nutrition contents of Polyporus ellisii were rich,and the contents of protein,crude fat,crude fiber and total polysaccharide were 2.45,0.22,1.40,61.30 g /100 g,which also contained K,P,Na,Se,Ca,Fe,Zn and other mineral elements,vitamin B1 and B2.The total amino acids of Polyporus ellisii was1829 mg /100 g,including 16 kinds of amino acids and 7 kinds of which was essential amino.Essential amino acids were 41.61% in total amino acids. Amino Acid Score( AAS),Chemical Score( CS),Essential Amino Acid Index( EAAI) and Nutritional Index( NI) were 68.00,60.00,81.69,77.34 and 2.00.Pharmacological amino acids content was67.14% in total amino acids. Polyporus ellisii was a kind of edible mushroom with good nutrition value and great potential for exploitation and utilization.