To provide a method for fractionating and purifying an aromatic polyamine mixture, capable of especially facilitating the fractionation and purification of a diphenylmethane-based aromatic polyamine mixture and obtaining isomers thereof in high purities or in concentrated state.

This method for fractionating and purifying an aromatic polyamine mixture comprises (a), in a first extraction step, mixing a starting polyamine mixture with a two-phased system consisting of (i) a hydrophobic solvent phase consisting essentially of a hydrophobic solvent, optionally an aromatic supplemental amine and optionally a polyamine, and (ii) an aqueous phase consisting of water, a strong acid, the supplemental amine and optionally the polymine, introducing the obtained mixture into the first extraction step for eluting a first aqueous phase and a first organic phase, (b) fractionating the first organic phase in a first distillation step, (c) neutralizing the first aqueous phase by adding a base, separating the obtained mixture into a second aqueous phase and a second organic phase, and (d) separating the second organic phase in a second distillation step into a distillate consisting essentially of the hydrophobic solvent and the supplemental amine and a distillation residue consisting essentially of a second polyamine fraction.