The recycling of ethylene-propylene diene-rubber (EPDM) waste was rea lized by activation of EPDM rubber was te particles surface with liquid EPDM polymers (LP) of low molecular weight. The optimal ratio of the waste EPDM rubber to LP was investigated whit re gards to the original EPDM properties. The degree of unsaturated ethylidene norbornene diene ter-monomer in LPs plays an important role in the activati on process and the cross-linking density of the reactivated materials and there fore the mechanical properties.