Formation of space charge in EPDM/ATH compounds and EPDM/XLPE laminates has been investigated. First, homocharge developes in the EPDM containing the ATH while hetero-charge developes in the XLPE. A broadly distributed interfacial charge peak is observed at the interface between EPDM and XLPE layers of EPDM/XLPE laminates. This interfacial charge changes depending on the treatment of laminates. Details of the results are described.