A method produces a 3-phenylisoserine derivative by protecting an amino group of a compound represented by General Formula (1) (wherein R1 represents a phenyl group, or a phenyl group having a substituent; R2 represents an alkali metal, alkaline earth metal, or nitrogen base; and R3 represents a hydrogen atom, methyl group, benzyl group, p-methoxybenzyl group, tert-butyl group, methoxymethyl group, 2-tetrahydropyranyl group, ethoxyethyl group, acetyl group, pivaloyl group, benzoyl group, trimethylsilyl group, triethylsilyl group, or tert-butyldimethylsilyl group) in water or a mixed solvent containing water to obtain a particular compound; extracting with a C4 ether-based solvent; replacing at least part of the C4 ether-based solvent with a C1-C4 aliphatic alcohol while removing the C4 ether-based solvent and water to perform esterification reaction; and isolating at 0 to 30° C. to obtain a 3-phenylisoserine derivative represented by General Formula (2).