In this paper, the fiber components and nutritients of three kinds of the fungus chaff after bagasse cultivation were determined and analyzed. The results showed that the fiber content of three kinds of pleurotus fungus chaff decreased significantly, while polysaccharide and crude protein increased obviously. The hemi-cellulose content of three kinds of fungus chaff is around 10%, the lignin content was less than 15%, the polysaccharide content was between 9~15 mg/g, the crude protein content was between 6%~10%.