Abstract: In this paper notched chapy impact strength and impact force-displacement curves of HDPE were measured and analysed at different temperatures.Also the SEM observation of fracture surface morphologies of HDPE specimens, which were impacted at different temperatures, were analysed.It reveals that there is a large crazed shear lips region at room temperature and the parapola morphology regions of smooth and corase strips alternate on the impact fracture surface of HDPE at the temperature between-35 and-10℃.The shear lips region indicates toughness fracture, but the corase strips without yielding deformation in the parapola morphology region exhibit a brittle cleavage.