Abstract: The water soluble components of Musk were investigated by chromatographic and ion-exchange methods. A peptide, named Antiinflammatory principle I with antiinflammtory action more than twenty times that of hydrocortisone, was isolated. The molecular weight of Antiinflammatory principle I was estimated to be about five to six thousand by molecular sieve on sephadex G-75 column. Antiinflammry principle I was shown to consist of about 15 amino acids by the amino acid automatic analyzer.