To establish the analysis method for the chemical constituents of muskrat and musk,determine the content of cyclopentadecanone,and analyze the similarities and differences of chemical compositions of muskrat and musk.The chemical components were analyzed and the content of cyclopentadecanone was determined by GC-MS.The peak was identified by NIST standard mass spectrometry library and relevant literature,and the relative content of each chemical component was calculated by peak area normalization method.Fifty-eight chromatographic peaks were detected from muskrat and 23 compounds were identified,accounting for 90.38% of the total peak area.A total of 43 chromatographic peaks were detected in musk and 19 compounds were identified,accounting for 91.21% of the total peak area.Both contain 6 identical ingredients,including tetradecanoic acid,cyclopentadecanone,hexadecanoic acid,oleic acid,octadecanoic acid,and cholesterol.Muskrat and musk mainly contain cycloalkanones,fatty acids and steroidal compounds,which have certain similarities in composition types.