New sulfur-containing polymers with high-refractive indices and low birefringences have been developed as UV-curable high-refractive polymer resins. The polymers derived from 2,7-bis[(2-acryloylethyl)sulfanyl]thianthrene (2,7-BAST) and 4,4'-bis[(acryloyloxyethylthio)diphenylsulfide (4,4'-BADS) were prepared by photopolymerization under UV irradiation Transparent UV-cured films were obtained in both cases Both polymers showed good thermal stability, such as a 5% weight-loss temperature at 355 degrees C under nitrogen and glass transition temperatures (T-g) in the range of 94-143 degrees C They also showed high-refractive indices of 1 6531 and 1 6645 at 632 8 nm and low birefringences of 0 0039 and 0.0069 in addition to high transparency in the visible region (C) 2010 Wiley Periodicals, Inc J Polym Sci Part A. Polym Chem 48 2604-2609, 2010