The present work describes a detailed investigation of the catalytic activity of Cesium salt of di-copper substituted phosphotungstate for the oxidation of styrene using tert-butyl hydroperoxide as the oxidant. Various parameters like time, catalyst amount, mole ratio of substrate to TBHP and temperature were optimized and good conversion (77.9%) was obtained along with high selectivity for the epoxide (51.6%). The catalyst was recycled and reused multiple times without significant loss of activity. A detailed kinetic study was carried out to gain a deeper understanding of the role of each component present in the reaction system. A plausible reaction mechanism was also proposed based on kinetic studies, ESR and Cyclic Voltammetry studies.