Abstract: The process producing propylene oxide by epoxidation of propylene with ethylbenzene hydroperoxide is one of the most promising methods in recent years. In order to select and achieve an optimum reaction equipment technologically, the mathematical models of the epoxidation reactor for plug flow, single-stage backmix and multi-stage equal-sized backmix in series have been founded in this paper based on the kinetic model and the effects of various flow patterns on the reaction have also been discussed. It is shown that multistage backmix reactor is a more perfect one for industrial equipment, and the optimum operating conditions are suggested. The mathematical model for multi-stage backmix flow has been verified experimentally in four-stage reactors. The experimental and calculated values agreed quite well with each other.