Recently, research on natural fiber reinforced polymer composites has gained importance due to the abundant sources of fibers that can be obtained at very low cost. In this study, wood plastic composite (WPC) materials is made by mixing (compounding) high density polyethylene (HDPE) and (ligno) cellulose fiber, i.e. rice husk reinforced with sawdust have been manufactured using a high volume process using counter rotating twin screw extruder. Different fire retardant agents have been employed in order to improve fire behavior in this study. The flammability and thermal stability of WPC-HDPE based in different compositions have been carried out by fire test method according to ASTM D635-06 and evaluated by thermo gravimetric analysis respectively. The properties of flexural strength and impact strength were also included.