A novel in-site H2O2 strategy is proposed for the liquid-phase epoxidation of propene catalyzed by titanium silicalite (TS-1). Said in-site H2O2 strategy is based on the direct synthesis of H2O2 from H2 and O2 under atmospheric pressure via nonequilibrium plasma reactions. Methanol is used to absorb H2O2 from the dielectric barrier discharge (DBD) reactor. Methanol also serves as the desired solvent for the liquid-phase epoxidation reactor. The efficiency of the integrated process for in-site synthesis of H2O2 reached 69% selectivity, and 62% yield with a nonexplosive H2/O2 mixture when the DBD reactor worked at an input power of 3.5 W (energy consumption 12.4 kWh/kg H2O2). The liquid-phase epoxidation of propene using the in-site H2O2 successfully proceeded over an 18 h time course under the conditions of 50 °C and 3.0 MPa, more than 92% H2O2 conversion and more than 93% PO selectivity were obtained. The two-reactor integrated process worked smoothly during continuous operation, no performance decay was observed for both the DBD reactor and the epoxidation reactor. These facts mean that our in-site H2O2 strategy for PO synthesis is promising. © 2007 American Institute of Chemical Engineers AIChE J, 2007