α-Trifluoromethyl-β-substituted-β-amino acids can be produced by allowing α-trifluoromethyl-β-substituted-α,β-unsaturated esters to react with hydroxylamine to convert α-trifluoromethyl-β-substituted-α,β-unsaturated esters into dehydrogenated closed-ring body of α-trifluoromethyl-β-substituted-β-amino acid, and by hydrogenolyzing the dehydrogenated closed-ring body. According to this production process, novel α-trifluoromethyl-β-substituted-β-amino acids which are free amino acids whose functional groups are not protected can be produced, in which β-position substituent is not limited to aromatic ring group or substituted aromatic ring group while the relative stereochemistry of α-position and β-position can be also controlled.