A plant disease controlling composition containing a pyridazine compound represented by formula (I): wherein R 1 represents a chlorine atom, a bromine atom, a cyano group or a methyl group, and R 2 represents a hydrogen atom or a fluorine atom, and at least one carboxamide compound selected from Group (A). Group (A): A group consisting of bixafen, isopyrazam, boscalid, fluopyram, fluxapyroxad, sedaxane, penflufen, flutolanil, mepronil, carboxin, thifluzamide, penthiopyrad and furametpyr.
