Novelheat-resistantN-substitutedpoly(benzimidazole imide)s (PBIIs)withgoodsolubilitywere synthesized via aC?Ncoupling reaction. A model reaction was carried out to assist in determining the optimal reaction conditions for the polymerization and to elucidate the chemical structures of the polymers. The structures of the resulting polymers were characterized by means of Fourier transform infrared and elemental analysis; the results showed good agreement with the proposed structures. The resulting PBIIs exhibited high glass transition temperatures (Tg >290 oC) and good thermostability (T5% >440 oC). The thermal behavior in air of the PBII polymers suggests that they can be considered as a new class of high performance polyimides.