Vinyl ester BisGMA [Bisphenol-A-glycidyldimethacrylate] resin has been modified by incorporating Titanium dioxide(TiO2)nanoparticles (0.5%-2% by weight). An ultrasonic mixing process was employed to disperse the particles into the resin system prior to casting and curing test specimens. From TEM investigation, it is found that the particles are nano size (5-60nm) and dispersed throughout the entire volume of the resin. Dynamic mechanical analysis was conducted for both the neat resin and nanocomposite. In dynamic mechanical analysis, nanocomposite shows increase in storage modulus (6%), and glass transition temperature (5.8%) from neat resin system. Thermogravimetric analysis shows 7.5% better thermal stability. In addition, the nanocomposite shows enhance in the stiffness by 5% in flexural loading. The Tg and flexural modulus of the nanocomposites were enhanced as the particle volume fraction was enhanced and than decreased.