An aromatic compound represented by the general formula Ar1X is reacted with a palladium compound and a phosphine derivative, in the presence of a first basic substance, thereby producing a palladium-complex compound represented by the general formula Ar1—PdL2X. This palladium-complex compound is reacted with a benzoic acid represented by the general formula Ar2—COOH, in the presence of a second basic substance, thereby producing another palladium-complex compound represented by the following general formula. The above palladium-complex compounds are useful as catalysts and can be produced easily by the above reactions. In the above general formulas, Ar1 is an aryl group; and X is a halogen that is fluorine, chlorine, bromine or iodine, trifluoromethanesulfonate group, an alkylsulfonate group having a carbon atom number of 1-4, or a substituted or unsubstituted arylsulfonate group; each L is independently a phosphine ligand; and Ar2 is an aryl group.