The porous Ultra-high Molecular Weight Polyethylene (UHMWPE) is designed to fabricate the roadside safety devices fixed on the conventional metal or concrete road highway guardrails. When the UHMWPE with pores is shocked, the material is compressed because the pores are closed and much energy is absorbed. Next, elastic deformation and plastic deformation happen further under the stress, kinetic energy is transformed into deformation energy further. The cushioning capacity of UHMWPE will be improved when the pores are induced. Then the vehicles will not be destroyed seriously when they bounce. On the other hand, it will be convenient to fix the roadside safety devices on the conventional metal or concrete road highway guardrails and the cost must be lower than changing the whole guardrails. Experimental results indicate that: UHMWPE exhibited excellent shock-absorbing capacity and it was a promising roadside safety material.