Abstract Using ultrasonic-aided submerged arc nanoparticle synthesis system, which is an innovative nanoparticle preparation method, this paper employs some major parameters together with robust design to investigate the optimized parameters, such as peak current, pulse duration, open voltage and amplitude of ultrasonic vibration, for producing TiO 2 nanoparticle suspension by using the least number of experiments. The experimental results indicate that evenly distributed TiO 2 nanoparticles can be manufactured. The pH value of isoelectric point (IEP) of the produced particle suspension is pH 5. The suspension is dispersed when the potential value of the suspension is distant from the IEP, or it would be aggregated when the potential value is close to the IEP. The produced TiO 2 nanoparticle suspension would absorb UV when the wavelength is 300–380 nm.