To provide a method for efficiently producing an asymmetrical cyclic fluoroolefin industrially useful as a medicinal or agricultural chemical intermediate, a raw material monomer for a fluorine-containing polymer or an electronic material.

The method for production of an alkylated asymmetrical cyclic fluoroolefin represented by formula (5) comprises reacting a cyclic fluorine compound shown by formula (1) with an alkylating agent shown by formula (2) to obtain an alkylated cyclic fluorine compound of formula (3) and then further reacting the obtained compound with another alkylating agent of formula (4). In formulas (1) to (5), R1 and R2 are not the same, and each 1-10C alkyl, 2-10C alkenyl, 2-10C alkynyl or 6-10C aryl; M is Li, MgCl, MgBr or MgI; and (n) is an integer of 1 to 3.