A thermally stable and optically active poly(amide-ester-imide) (PAEI) was prepared from diol: N,N'-(1,3,5,7-tetraoxo-5,7-dihydropyrrolo[3,4-f]isoindole-2,6-(1H,3H)-diyl)bis-(4-hydroxybenzamide). The structure of the polymer was determined by means of H-1 NMR and Fourier transform infrared spectroscopy (FT-IR), elemental analysis; also it was studied with specific rotation technique, X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). Then, three series of PAEI/modified TiO2 nanocomposites (NC)s with 5, 10, and 15 % of TiO2 nanoparticles (NP)s contents were prepared via ultrasonic irradiation technique. The properties of the synthesized NCs were studied by FT-IR, XRD, FE-SEM, transmission electron microscopy, UV-vis spectroscopy and thermogravimetric analysis methods. It was found that the NCs exhibit enhanced thermal properties compared with the neat PAEI.