Polyamine compositions for welding are provided, having excellent weldability, heat resistance, and hydrolysis resistance. Compositions of (A) an aromatic polyamide in which the molar fraction of aromatic monomers among the monomer components making up the polyamide is at least 0.2, and (B) an aliphatic polyamide, wherein the weight ratio of (A) and (B) is from 99:1 to 5:95 are described.