An object of the present invention is to provide an agricultural chemical formulation which is able to control release of an agricultural chemical active ingredient. This agricultural chemical formulation includes a composition, containing an agricultural chemical active ingredient, styrene-maleic anhydride copolymer or mixture of styrene-maleic anhydride copolymer and polymer having repeating units derived from rosin or derivative thereof or salicylic acid or derivative thereof, and a release controller (a water-soluble polymer, a hydrophobically-treated silicon oxide, or a surfactant), forming a compatible state or matrix.