Vinylidene chloride/ethyl acrylate (V/E) copolymers were prepared by photopolymerization using uranyl ion as a photosensitizer at room temperature. Copolymers were characterized by chlorine estimation, gel permeation chromatography, 1H- and 13C-NMR, 2D heteronuclear single quantum correlation (HSQC), and homonuclear 1H-2D double quantum filter correlation spectroscopy (DQF-COSY). Reactivity ratios for the copolymerization of V with E were calculated using the Kelen-Tudos (KT) and the nonlinear error in variables (EVM) methods. The reactivity ratios obtained from the EVM methods are rV = 0.80 ?0.15 and rE = 0.87 ?0.04. The microstructure was calculated in terms of the distribution of V- and E-centered triad sequences from 13C{1H}-NMR spectra of the copolymers. 2D HSQC was used to analyze the complex 1H-NMR spectrum and 2D COSY shows the various bond interactions, thus inferring the possible structure of the copolymers.