Merox process widely uses in mercaptan removal and conversion of petroleum distillates as well as natural gas. In Tehran Oil Refinery, Merox extraction uses for mercaptan removal from LPG. The main purpose of this work was study of suitability of the Merox process for mercaptan removal from gasoline by using process simulation. Unfortunately, the process is not available in conventional softwares such as Aspen and Hysys. Therefore, first a model has been suggested and verified with the available operational data of the working unit, and then the model used for suitability of the process for mercaptan removal from gasoline. In the modeling, governing, equilibrium and kinetic equations have been derived and solved. An extension has been developed for Merox process calculations by Microsoft Visual Basic 6.0 and then connected and run in Hysys 3.1. In modeling of the extraction tower, it needed to know the oxidation reactions kinetics data of three types of mercaptans. Since the data are not available in literature, the kinetics data obtained experimentally for catalytic oxidation of mercaptans in presence of alkaline solution. Results show that the kinetics data can be fitted well with first order reaction. In order to verify the Merox unit computer simulation, LPG introduced to the program as a feed. The simulation results showed a good agreement with the operational data of Merax unit of Tehran Oil Refinery. Then, the visbreaker gasoline was introduced as a feed to the simulated unit. Simulation results indicated that light mercaptans, which were available in the gasoline, could be eliminated by the Merox extraction unit; where as the heavier mercaptans in the gasoline can be eliminated according to their relative solubility in water. Furthermore, regarding the obtained results, some methods have been presented for elimination of the heavy mercaptans from the gasoline. Key words Merox process, mercaptan, modeling, simulation, visbreaker gasoline