The results of an investigation of the epoxidation of styrene by cumyl hydroperoxide are presented. It has been established that the introduction of boron-containing additives improves the parameters of the process. The best inhibitors of styrene polymerization under epoxidation conditions are phenol-type compounds. A study has been made of the influence of different factors on the epoxidation of styrene by cumul hydroperoxide. The results of kinetic investigations of the reaction are given.