A new aromatic diacid monomer containing pyridine unit,4-phenyl-2,6-bis[4-(4-carboxyphenoxy)phenyl]pyridine 3,was successfully synthesized in three steps,starting from 4-hydroxyacetophenone.The corresponding pyridine-containing polybenzi-midazole was prepared via polycondensation of 3 with tetraaminodiphenyl ether(TADE)in poly(phosphoric acid)(PPA).The resulting polybenzimidazole exhibits excellent solubility,good thermal stabilities and high thermal resistance.