A plant disease controlling composition, containing a carboxamide compound represented by formula (I): wherein R 1 represents a hydrogen atom or a methyl group and R 2 represents a methyl group, a difluoromethyl group or a trifluoromethyl group, and a pyridazine compound represented by formula (II) wherein A 1 represents a chlorine atom, a bromine atom, a cyano group or a methyl group, and A 2 represents a hydrogen atom or a fluorine atom.
