Abstract: In order to evaluate the synergistic effect between initiator and silane agent, silane modified poplar veneer/HDPE film composites were prepared using HDPE film as wood adhesives, silane A-171(vinyltrimethoxysilane)dicumyl peroxide(DCP)as veneer modifier. Physical-mechanical properties of composites under different initiator DCP dosage(0, 0.05%, 0.10% and 0.15%)were investigated by mechanical testing machine, dynamic mechanical analysis(DMA)and scanning electronic microscope. The results showed that silane-treated poplar veneer and HDPE film were closely entangled by means of a chemical bond resulted from oxy radicals generated by DCP, which contributed to forming enhanced interlock and a stronger interface between the two phases. This kind of bonding interface in turn resulted in much higher mechanical properties, water-resistance and thermal stability. When DCP addition reached 0.15%, tensile strength, wood failure, modulus of rupture and modulus of elasticity values of the composites increased from 1.02 MPa, 2%, 60.10 MPa and 5 102 MPa to 2.07 MPa, 95%, 77.20 MPa and 6 822 MPa, respectively. It also caused water absorption and thickness swelling value decreased from 77.80% and 5.79% to 53.75% and 4.09%, respectively. Thermal stability of silane modified poplar veneer/HDPE film composites were also strengthened with the increase of DCP dosage by DMA results. The retention rate of storage modulus value at 130 ℃ increased from 44.19% to 88.34% when DCP content rose from 0 to 0.15%. This trend also applied to the bonding interface failure temperature, which lagged from 147 ℃ to 197 ℃.