Abstract: The high density polyethylene（HDPE）/ramie fiber composites were prepared by twin-screw extruder and injection molding, and the ramie fiber content to the effect of composite material performance was researched. The interfacial bonding between the ramie fiber and HDPE was enhanced by introducing compatilizer and increasing the ramie fiber. On the TGA showed that the composites can be applied to the environment with temperature between 0-100℃，while the DSC showed that introducing ramie fiber decreased the crystallinity of HDPE. The thermostability of the composites was improved by increasing the ramie fiber.

Key words: high density polyethylene, ramie fiber, reinforcement, composite, thermostability, crystallinity