Abstract: The wood flour-starch/poly (lactic acid)(PLA) composites were prepared by melt extrusion method with poplar wood flour, corn starch and PLA as raw material, glycerol as compatibilizer. The effect of wood flour contents on interfacial compatibility, thermal properties, mechanical properties, rheological properties and water absorption rate of composites were studied. The results show that with the increasing of wood flour contents, the interfacial compatibility between PLA and wood flour decreases, the thermal stability of wood flour-starch/PLA composites reduces, storage modulus, loss modulus and complex viscosity gradually increase. With the increasing of wood flour contents, the tensile strength and bending strength of wood flour-starch/PLA composites first increase then decrease, and reach the best values at 40.65 MPa and 60.91 MPa with 18wt% wood flour content. With the increasing of wood flour contents, the elongation at break of composites reduces gradually from 9.64% to 5.97%, and the water absorption rate increases observably from 5.38% to 13.43%.