A 4-amino-6-alkynyloxypyrimidine compound, which is represented by the formula (I)and has an effect of controlling a harmful organism, can be produced in a high yield by reacting a 4,6-difluoropyrimidine compound with an alkynol compound in an alkylbenzene in the presence of an organic salt and potassium carbonate and reacting the resulting compound with an amine compound without isolating the resulting compound.