A series of poly(anmide-imide)s IIIa-m containing flexible isopropylidene and ether groups in the backbone were synthesized by the direct polycondensation of 4,4＇-[1,4-phenylenebis(isopropylidene-1,4-phenyleneoxy)]dianiline (PIDA) with various bis(trimellitimide)s IIa-m in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. The resulting poly(,amide-imide)s had inherent viscosities in the range of 0.80-1.36 dL/g. Except for those from the bis(trimellitimide)s of p-phenylenediamine and benzidine, all the polymers could be cast from DMAc into transparent and tough films. They exhibited excellent solubility in polar solvents. The 10% weight loss temperatures of the polymers in air and in nitrogen were all above 495 degrees C, and their T-g values were in the range of 201-252 degrees C. Some properties of poly(amide-imide)s III were compared with those of the corresponding poly(amide-imide)s V prepared from the bis(trirmellitimide) of diamine PIDA and various aromatic diamines.