Abstract The phenol resin is useful as support of the solid phase peptide synthesis. Its use is particularly advantageous for the synthesis of the N-protected peptide fragments, and those which have the intramolecular disulfide bond, such as oxytocin. In the latter case, the application of S-ethylmercapto group as the protector of thiol group of cysteine residue was combined successfully. Oxytocin and physalaemin derivatives were thus synthesized.