To provide a method for producing a Δ2-1,2,4-oxadiazoline derivative or its salt having excellent insecticidal action in high yield and excellent industrial mass-productivity.

The method for the production of the oxadiazoline derivative is expressed by reaction formula [X1 is a halogen atom; R1 is a (substituted) alkyl, a (substituted) acyl or ClCO; R2 is a halogen, a 1-6C haloalkyl, a 1-6C haloalkoxy or phenyl group which may be substituted with a 1-6C haloalkyl; A is nitrogen atom or =CR3 (R3 is Cl or CN); R4 is a 1-6C alkyl or a 1-6C haloalkyl; (n) is 0, 1 or 2; and X2 is a halogen atom].