NEW MATERIAL:A compound shown by the formula.

USE: An intermediate for synthesizing a low toxic novel cysteine-containing physiologically active peptide useful an antiviral agent, cytostatic agent and NK cell enhancer and an intermediate for synthesizing (pro)γ-interferon, etc. Having improved shelf stability.

PREPARATION: For example, a carboxylic acid group of α-amino-protecting group-containing amino acid is bonded to a substrate such as polystyrene resin crosslinked with divinyl benzene and the α-amino-protecting group is removed. Then, the deprotected free amino group is reacted with a second amino acid. Then, the deprotection and introduction of amino acid are repeated to give the aimed peptide chain and the covalent bond between the carboxylic acid group of carbon-end amino acid of peptide and the resin is cleft. The reaction is preferably carried out under a strongly acidic condition.