Abstract: Malefic anhydride(MAH)was introduced into the reactive extrusion system of PE-HD/bagasse, and properties of resulted product were compared with those resulted by two other coupling agents, amino-silane and isopropyl triisostearoyl titanate. It was found that the grafting of MAH occurred during the extrusion, and consequently the compatibility between PE-HD and bagasse was improved. With addition of 6% MAH，the tensile strength of the composites increased by 120%，impact strength by 24%，and water uptake reduced to 0. 5%.

Key words: high density polyethylene, bagasse, composite, reactive extrusion, malefic anhydride