Abstract: The PE-LD/eucalyptus flour powders wood plastic composites were prepared by a twin-screw extruder and an open-type refine machine using PE-LD-g-MAH a compatibilizer, and the effects of molding temperature, molding time, PE-LD-g-MAH concentration and preparation methods on the tensile strength and notched impact strength of the composites were investigated. The morphology and chemical structure of the composites were characterized by SEM and FTIR. The results indicated that the optimum molding temperature and time is 160 ℃ and 10 min for the preparation of composites, and the use of the open-type refine machine and PE-LD-g-MAH led to the excellent mechanical properties for the composites due to a better dispersion and interface bonding strength of eucalyptus flour powders. The tensile strength of composites increased from 16.53 MPa to 24.46 MPa, and their notched impact strength increased from 2.04 kJ/m2 to 4.58 kJ/m2. The improvement in mechanical properties was due to the enhanced interface-bonding strength derived from the esterification reaction between PE-LD-g-MAH and the hydroxyl groups on the surface of eucalyptus flour powders.