To provide an industrially useful new optically active isoxazoline derivative and to provide a method for producing the derivative.

The method for producing the isoxazoline derivative comprises reacting an oxazolidinone derivative represented by formula (3) with a nitrile oxide derivative obtained from a nitrile oxide precursor represented by general formula (4) (wherein R1 is a methyl group, an ethyl group, a 3-10C alkyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a 3-10C alkoxycarbonyl group or a phenoxycarbonyl group) or formula (5) (wherein R2 to R6 are each independently a hydrogen atom, a methyl group, an ethyl group, a 3-6C alkyl group, a methoxy group, an ethoxy group, a 3-6C alkyloxy group, a phenyl group, a phenyloxy group, a fluorine atom, chlorine atom, a bromine atom, an iodine atom or a nitro group) in the presence of a Lewis acid.