The effective utilization of lignin waste has been a main concern in the bio-ethanol industry which uses straw and stalks as feedstock. In this study the lignin waste was incorporated into high density polyethylene (HDPE) to make composites by extruded pellet fabrication and thermoform process. With the increasing of the lignin content from 55% to 75%, the static flexural strength of the resulting blends was hardly influenced, but the tensile strength decreased 42%. The mechanical and dimensional stability tests both showed that the addition of 4% MAPE promoted the interfacial bonding between lignin and HDPE. The DSC analysis showed the presence of lignin scarcely influences the thermal behavior of pure HDPE and the composites.