The present invention relates to an aqueous pesticidal composition having excellent pesticidal activity, particularly a pesticidal composition comprising a pesticidal active ingredient, a carboxy-modified methyl methacrylate-butadiene copolymer, a surfactant and water, wherein the amount of the carboxy-modified methyl methacrylate-butadiene copolymer is 20 - 100 parts by weight relative to 100 parts by weight of the pesticidal active ingredient and the amount of the surfactant is 0.1 - 50 parts by weight relative to 100 parts by weight of the pesticidal active ingredient.
