Modeling of esterification of acetic acid with n-butanol in the presence of Zr(SO4)(2). 4H(2)O coupled pervaporation was studied in this paper. The influence of several process variables, such as process temperature, initial mole ratio of acetic acid over n-butanol, the ratio of the effective membrane area over the volume of reacting mixture and catalyst content, on the esterification was discussed. The calculated results for the conversion of n-butanol to water and permeation flux were consistence with the experimental data. The permselectivity and water content can be roughly estimated by the model equations.