The present invention provides the agricultural chemical-spreading agent composition, containing: (A) a polysaccharide in an amount of 5 to 30% by weight (B) a polyoxyalkylene sorbitan fatty acid ester in an amount of 5 to 40% by weight and (C) at least one nonionic surfactant selected from polyoxyalkylene alkyl ethers, sorbitan fatty acid esters, and silicone surfactants in an amount of 5 to 40% by weight, wherein the component (A) has a viscosity of not less than 5000 mPa·s in the form of a 5% by weight aqueous solution at 25° C., and a weight ratio of contents of the component (A) to the sum of components (B) and (C), (A)/[(B)+(C)], is 10/90 to 40/60.
