The chemical composition of blue sheep (Pseudois nayaur) muscle tissues from the Helan Mountains was analyzed to quantify its nutritional content. Male and female blue sheep differed with respect to the content of phosphorus, zinc, amino acids, and fatty acids. Blue sheep meat was found to be a good source of protein and minerals, particularly calcium, phosphorus, and copper. Compared with the ideal EAA/TAA ratio (about 40%) recommended by the FAO/WHO, the protein of blue sheep was of high quality with a high EAA/TAA ratio (39.3% males, 39.2% females). The amino acid score and chemical score revealed that valine was the limiting amino acid and lysine content was high. Blue sheep meat was also found to be a good source of linoleic acid and linolenic acid.