In this work, bio-inspired Au nanoparticles (NPs) were loaded through an ionic-liquid-enhanced-immobilization method onto TS-1 support, leading to efficient Au/TS-1 catalysts for gas-phase propylene epoxidation in the presence of O-2 and H-2. Specifically, the mesoporous TS-1 was synthesized by a hydrothermal method using nanosized TS-1 (size of similar to 220 nm) as seeds, and the support was then etched with acid (HCl or HNO3). Both the pristine TS-1 and Au/TS-1 catalysts were fully characterized to understand the effects of preparation conditions on the catalytic performance in propylene epoxidation. Interestingly, it was found that the amount of Lewis acid sites in the seed-induced TS-1 was greater than that on the control sample formed without seed; more importantly, the size of the loaded Au NPs can be regulated by changing the amount of Lewis acid site. Furthermore, we have demonstrated that the post-treatment of TS-1 with appropriate acid sites could enhance the propylene conversion and propylene oxide (PO) selectivity. Graphic