The invention provides a plant disease control composition including active ingredients of (RS)-N-[2-(1,3-dimethylbutyl)thiophene-3-yl]-1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxamide (common name: penthiopyrad) and at least one fungicidal compound other than penthiopyrad, and a plant disease prevention method wherein such a compound is applied to plant seeds or soil. According to the invention, a composition and a prevention method are provided which demonstrate a prevention effect against plural types of disease pathogenic microbes, and also demonstrate a preventing effect to currently emerging resistant pathogenic microbes, when applied to plant seed or soil.