Two series of new flame-retardant polyaryl phosphoramide esters were synthesized by low-temperature solution polycondensation from arylphosphorodichlorides with 3,4-bis(4-aminophenyl)2,5-diphenylfuran and 2,5-bis(4-aminophenyl)3,4-diphenylthiophene. The polymers were characterized by IR, H-1, C-13, and P-31 NMR spectroscopy and elemental analysis. The thermal stability and flammability were studied by thermogravimetry and limiting oxygen index, respectively.