Hemoglobin from the cobra snake, Naja naja naja, was isolated and its chains separated on a CM-cellulose column. The separation profile revealed an α and two β chains having the molar proportions of [α]2,[β1]1,[β2]1. The N-terminal amino acid sequence of the intact chains and of the CNBr peptides were carried out. The β2 chain was found to be heterogeneous comprising a minor component amounting to 11%. This later showed changes at two positions 9 and 14 in the first 30 residues sequenced.