In the epoxidation system of [pi -C5H5NC16H33](3)[PW4O16]/molecular oxygen/recyclable reductant (2-ethylanthrahydroquinone), cyclohexene, terminal olefins and allyl chloride all underwent epoxidation reactions smoothly under mild conditions. Good selectivities to epoxides and high reductant utilization efficiencies (72.6-94.5%) were achieved. From 1-dodecene to 1-hexene, the epoxidation reactivity of the olefin and the utilization efficiency of the reductant increased with the decrease of carbon atoms in terminal olefins. Studies showed that H2O2 produced by the oxidation of 2-ethylanthrahydroquinone with molecular oxygen was the key intermediate that afforded the direct epoxidation of the substrate.