A new class of aromatic poly(urea-imide)s having biphenylene pendant group was prepared by the diphenyl azidophosphate (DPAP) activated one-pot polyaddition reaction of a preformed imide ring-containing dicarboxylic acid, 4-p-biphenyl-2,6-bis(4-trimellitimidophenyl)pyridine (1) with various aromatic diamines. A model compound was also synthesized by the reaction of diimide-dicarboxylic acid 1 with two mole equivalents of aniline. In this direct method the polymers were prepared by polyaddition reactions of the in situ-formed diisocyanate with the aromatic diamines. The inherent viscosities of the polymers were measured in the range of 0.11–0.15 dL g^-1. The ultraviolet kmax values of the poly(urea-imide)s were also determined. Furthermore, crystallinity of the resultant polymers was evaluated by wide-angle X-ray diffractionmethod, and they exhibited nearly a noncrystalline nature. All of the resulting polymers exhibited excellent solubility in common polar solvents. The glass transition temperatures of the polymers determined by DSC thermograms were in the range 241–272 ºC. The temperatures at 10% weight loss from their TGA curves were found to be in the range 406–437  ºC in nitrogen.