Globin prepared from hemoglobin of adult tupai (Tupaia glis) was separated into α and β polypeptide chains by CM-cellulose column chromatography. The S-aminoethylated α polypeptide chain and S-carboxymethylated β polypeptide chain were each digested with trypsin, and the sequences of all the peptides thus obtained were established. The ordering of these tryptic peptides in the α and, β polypeptide chains was deduced from the homology of their primary structures with that of human adult hemoglobin. In this way the primary structures of the α and β polypeptide chains of tupai hemoglobin were established; 27 amino acids in the α polypeptide chain and 26 in the β polypeptide chain differ from those in human adult hemoglobin.