This invention provides an agricultural chemical composition comprising an enhancer for agricultural chemicals, which is excellent in stability even when compounded at high concentration, and exerts an excellent effect-enhancing action on agricultural chemicals. A specific amine oxide having a C6-30 alkyl or alkenyl group or an alkylphenyl group having a C6-17 alkyl group, and an amide alkyl group or oxyalkylene group is used as the enhancer for agricultural chemicals.