Anatase phase of Titanium dioxide nanoparticles (TiO2-nps) was prepared by new route using ultrasound assisted sol-gel method with operating conditions (40 kHz, 350 W). The crystal phase, morphology, surface area, thermal properties, and optical properties of TiO2-npswere characterized by X-ray diffraction (XRD), FTIR spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), BET & BJH surface analysis, thermogravimetric analysis (TGA), and UV-Vis absorption spectroscopy. The synthesized nanoparticles have mesopores-micropores surface with pure anatase phase and small crystal size (approximately 11nm).The spherical shape of TiO2-npscan be examined through the SEM, TEM, and AFM images. The synthesized TiO2-nps have highly thermal stability (mass loss ≈ 0 until 542°C), the surface area and band gab values ofTiO2-nps were calculated to be64.041 m2/g and 3.2 eV respectively.