New diimide–dicarboxylic acids, ie 4-phenyl-2,6-bis(4-trimellitimidophenyl)pyridine and 4-p-biphenyl-2,6-bis-(4-trimellitimidophenyl)pyridine, were synthesized by the condensation reaction of 4-phenyl-2,6-bis(4-aminophenyl)pyridine and 4-p-biphenyl-2,6-bis(4-aminophenyl)pyridine with trimellitic anhydride in glacial acetic acid or dimethylformamide. Themonomers were fully characterized by FT-IR and NMR spectroscopies, and elemental analyses. A series of novel poly(amide–imide)s with inherent viscosities of 0.68–0.87 dl g⁻¹ was prepared from the two diimide–diacids with various aromatic diamines by direct polycondensation. The poly(amide–imide)s were characterized by FT-IR and NMR spectroscopies. The λmax data for the resulting poly(amide–imide)s were in the range of 260–292 nm. These polymers exhibited good solubilities in polar aprotic solvents. The 10 % weight loss temperatures are above 485 ºC under a nitrogen atmosphere.