NEW MATERIAL:The title derivative of formula I (X is benzyloxycarbonyl, t-butoxycarbonyl or acetyl; Y is H, 1-4C alkyl free from quaternary carbon, benzyl, 2-methylthioethyl, etc.) or of formula II.

EXAMPLE: An N-benzyloxycarbonylalanine glycidyl ester.

USE: A raw material for synthesizing polymeric materials and medicines, modifier for polymeric materials.

PREPARATION: For example, N-benzyloxycarbonyl-L-alanine is dissolved in dichloromethane, and while cooling the resultant solution with an ice bath, a dichloromethane solution containing glycidol and 4-dimethylaminopyridine is added to the above solution in the presence of a condensation agent such as N,N'-dicyclohexylcarbodiimide to carry out reaction, thus giving the objective derivative of the formula I.