A new heat-resistant polymer has been synthesized from N-(4-carboxy phenyl) trimellitimide and benzidine. The polymer was characterized by nitrogen analysis, IR spectroscopy, density, viscosity, and x-ray measurements. The polymer was found to be insoluble in all polar organic solvents and only soluble in formic acid and concentrated H2SO4. The solubility parameter value has been determined. Thermal studies show that the polymer is thermostable up to 300°C. The electrical properties have also been measured.