When an organosilicone surface active agent is added to a pesticidal aqueous suspension composition containing an active ingredient compound of a sparingly water-soluble pesticide for the purpose of attaining activity enhancement and formulation, the following problems arise: such that (1) the viscosity of the composition increases (2) a large amount of foams due to the organosilicone surface active agent tends to generate at the time of preparation of a spray solution and the like. Thus, measuring the composition and preparation of a spray solution were difficult. The present invention provides a pesticidal aqueous suspension composition including (a) an active ingredient compound of a sparingly water-soluble pesticide, (b) an organosilicone surface active agent, (c) a viscosity-reducing agent, (d) an antifoaming agent, (e) a pH adjustor and (f) a dispersant, which is suppressed in increasing in the viscosity, is easy to measure, hardly generates foams at the time of dilution with water and is easy to prepare a spray solution.
