Abstract 1) Polyglycine dispersed on the surface of kaolinite was prepared by the polycondensation of N-carboxylic anhydride or glycine ester on kaolinite. 2) It was concluded that a part of glycyl residues in polyglycine dispersed on kaolinite was easily converted to seryl or threonyl residues by the condensation with formaldehyde or acetaldehyde. 3) The condensation occurred not only at amino terminal glycyl residues but also at non-terminal glycyl residues.