Abstract: With the purpose to study the rheological behavior and interface fusion of functionalized wood powder/low density polyethylene (LDPE) thermal plastic masterbatch, benzylation poplar wood powder(Wd-Ar) was synthetized after alkali pretreatment with ultrasonic-assisted, then Wd-Ar/LDPE thermal plastic masterbatch were prepared by co-blend and extrusion method. The variations on interfacial compatibility, thermal melt flowability, thermal softening point, heating fusion features and changes of surface free energy of Wd-Ar/LDPE thermal plastic masterbatch were examined. Results show that, compared with that of untreated wood flour (Wd), SEM shows the enhanced interface integration of plastic masterbatch and LDPE. XRD result analysis shows that crystallinity of thermal plastic masterbatch decreases, thermal softening point decreases, melt flow rate improves, total surface free energy decreases, nonpolar component free energy increases. Wd-Ar is more effective in reducing the balance torque of LDPE combined materials, while improving melt processing performance, interface integration and mechanical properties of the composites effectively. When the content of LDPE is 20wt%, the tensile strength, breaking elongation and flexural strength of Wd-Ar/LDPE composite increase by 2.55, 4.55 and 2.27 times, respectively, which indicate that the interface bond abilities between Wd-Ar and LDPE increase.