sHigh refractive index homogeneous hybrid materials were successfully prepared. The polymer matrix was the copolymer of methyl methacrylate, sulfur-containing monomer 2,2'-mercaptoethylsulfide dimethacrylate (MESDMA), and nanotitania was prepared by in situ solgel process of titanium n-butoxide. The transmission electron microscope (TEM) study suggested that the hybrid was homogeneous without inorganic agglomerate, and the inorganic particles were 4-7 nm. The refractive index was similar to 1.75 when the inorganic content of the hybrid film reached to 70 wt %, and the transmittance maintained up to 85%. The sulfur-containing monomer was used to improve the refractive index, also, it was a crosslinking reagent, which improved the film-forming ability of the hybrid. After copolymerized with MESDMA, the film-forming ability of the hybrid was better than the one without MESDMA. Even if the inorganic content exceeded 75 wt %, the films kept integrity. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3498-3503, 2009