There has been a problem such that if a water-based pesticidal suspension containing, as an active ingredient, an agricultural chemical having a high aqueous solubility, particularly an agricultural chemical having an aqueous solubility exceeding 500 mg/L at 20℃, is stored for a long period of time, the active ingredient particles tend to grow and become coarse, whereby a stabilized suspension is hardly obtainable.To solve such a problem, the present invention provides a water-based pesticidal suspension comprising (a) an agricultural chemical or its salt having an aqueous solubility of from 500 mg/L to 6,000 mg/L at 20℃, (b) a polycarboxylate type surfactant, (c) a sulfonate type surfactant, and (d) water.本發明之課題在於：若將以水溶解度高的農藥化合物，尤其於20℃之水溶解度超過500mg/L的農藥化合物為有效成分的水性懸浮狀有害生物防除用組成物長期保存，農藥有效成分粒子會於保存中成長、大型化，而無法獲得安定的組成物。本發明提供一種水性懸浮狀有害生物防除用組成物，其係含有：(a)於20℃的水溶解度為500mg/L~6000mg/L的農藥化合物或其鹽、(b)聚羧酸型界面活性劑、(c)磺酸型界面活性劑，及(d)水。
