To obtain a mixture of compounds represented by a plurality of particular formulas by continuously subjecting compounds represented by particular formulas to catalytic hydrogenation using hydrogen under a specified pressure at a specified reaction temperature and employing a fixed bed catalyst including ruthenium supported by a Al2O3 support treated with a specified compound.

Diamine-toluene represented by Formula III is subjected to catalytic hydrogenation using hydrogen under a pressure of 20-500 bar of H, at a reaction temperature of 150-260°C to prepare a mixture of amino-methyl- cyclohexanes and diamino-methyl-cyclohexanes represented by Formulas I, II. Aluminum oxide, preferably γ-Al2O3 is used as a support. Rare earth metal compounds and manganese compounds are added to the support before undergoing impregnation of a rutheniumcontaining solution, and alkaline metal hydroxides and/or alkaline earth metal hydroxides are additionally added to prepare catalyst.