Object The invention provides a labor-saving self-water-surface-spreading chemical formulation (SS: spreading suspension) of a novel formulation type different from any conventional type, wherein when poured into a water surface of an water environment, the chemical formulation self-spreads all over the water surface within a short time even if there is no or little water flow and water movement, allowing for more labor-saving and homogeneous spreading in application of chemical formulations to water environments than in Jumbo formulations and water-surface-spreading formulations. Solution To achieve the above object, the present invention is a labor-saving self-water-surface-spreading chemical formulation that is a fluent mixture at least containing: a liquid, granular or powdery chemical ingredient and a liquid-form spreading ingredient that dissolves in or adsorbed to the chemical ingredient, or coats the chemical ingredient, and spreads the chemical ingredient at the water surface and is not either soluble, emulsible or suspensible in water which is 20 times the weight thereof and of a temperature higher than 0°C and lower than 40°C. Representative Drawing Fig. 1
