Abstract: The kinetics of the synthesis of ethyl tertiary-butyl ether(ETBE) from ethanol and isobutene in C4 streams with cation exchange resin as catalysts was investigated. A kinetics model based on Redeal-Eley (R-E) reaction mechanism was established, which showed excellent agreement with experimental results. Reaction rate has no relation with the concentration of ethanol and pseudo-first order kinetics could be used to process concentrations of isobutene and ETBE in the reaction mixtures.