Organic nano-titanium dioxides (TiO 2 ) were prepared with tetrabutyl titanate as precursor, hydrochloric acid as catalyst and γ -methacryloxpropyltrimethoxysilane (KH-570) as modifier, and the organic nano-TiO 2 /acrylate composite emulsions were synthesized by in-situ emulsion polymerization. The structure and properties of organic nano-TiO 2 and organic nano-TiO 2 /acrylate composite emulsions were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), thermogravimetry (TG) and transmission electron microscopy (TEM). The results showed that KH-570 was grafted successfully to the surface of nano-TiO 2 , and the crystal of organic nano-TiO 2 was anatase form, the smallest particle diameter was 10.2 nm. The organic nano-TiO 2 was dispersed averagely in the polyacrylate matrix, the composite latex particles seemed like "strawberry" and the heat resistance of the composite latex films was improved with the addition of organic nano-TiO 2 .