The present invention provides a composition for controlling a plant disease comprising a pyridazine compound represented by formula (1) wherein X represents a fluoro atom or a hydrogen atom, and a carboxamide compound represented by formula (2), and a method for controlling a plant disease, comprising a step of applying each effective amount of the pyridazine compound represented by the above formula (1) and the carboxamide compound represented by the above formula (2) to a plant or soil for cultivating the plant, the composition and method having excellent control efficacies against plant diseases.
