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°C, 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 °C, (b) a polycarboxylate type surfactant, (c) a sulfonate type surfactant, and (d) water.