The present invention provides a substituted pyridine compound represented by the formula (I) or a salt thereof, a pest control agent containing a substituted pyridine compound represented by the formula (I') or a salt thereof as an active ingredient, an agricultural and horticultural insecticide, miticide, nematicide, or soil pesticide containing the substituted pyridine compound represented by the formula (I') or a salt thereof as an active ingredient, and a method for controlling a pest by applying the substituted pyridine compound represented by the formula (I') or a salt thereof.[Chem 1](in the formulae (I) and (I'), for each substituent, see Description).本發明提供式(I)表示之取代吡啶化合物或其鹽、含有式(I’)表示之取代吡啶化合物或其鹽作為有效成分之有害生物防治劑、含有式(I’)表示之取代吡啶化合物或其鹽作為有效成分之農園藝用殺蟲劑、殺蟎劑、殺線蟲劑或殺土壤害蟲劑、以及施用式(I’)表示之取代吡啶化合物或其鹽來防治有害生物之方法。[化1]式(I)及式(I’)中，各取代基參照說明書。
