To provide an economically advantageous distillation method capable of preparing a high quality oxystyrene derivative such as PTBS (p-tert-butoxystyrene), PACS (p-acetoxystyrene) or MTBS (m-tert-butoxystyrene) at a high recovery rate, which derivative is inhibited in discoloration and thus has dissolved conventional problems in the prior art, by inhibiting the decomposition and discoloration of the oxystyrene derivative and a polymerization inhibitor, without impairing a polymerization inhibiting effect of a nitroso compound or a nitro compound which is a polymerization inhibitor.

In a method comprising distilling an oxystyrene derivative in the presence of a nitroso compound and/or a nitro compound, the distillation is carried out in the coexistence of an epoxy compound.