Abstract: Epoxidations of styrene and unsaturated fatty acid methyl esters(FAMEs) were studied using bicarbonate-activated hydrogen peroxide(BAP) system.The effects of bicarbonate,surfactants,adding modes of feedstocks,reaction time,the amount of H₂O₂ and reaction temperature on H₂O₂ decomposition and olefin epoxidation were investigated,respectively.When the molar ratio of n(styrene):n(H₂O₂):n(NaHCO₃) is 1:10:0.25,the adding amount of cation surfactant cetyl trimethylammonium bromide(CTAB) is 1% mass fraction,the reaction temperature is less than 35℃,the reaction time is 6 h with slowly adding 30% H₂O₂ under stirring,the yield and selectivity of styrene oxide were up to 85% and 96%,respectively,and only a minor amount of benzaldehyde was formed.Cation surfactant CTAB,which carries active oxygen species HCO₄^-,can significantly promote the styrene conversion.However,the electrophilicity of active oxygen species HCO₄^- is not enough to epoxide unsaturated FAMEs molecules with straight chains or containing an electron-defect C=C bond.