Surface　plasmon　polaritons　(SPPs)　have　attracted　intensive　attention　for　the　unprecedented　developments　of　light-matter　interactions　in　optics　and　photonics,　providing　a　feasible　method　for　light　confinement　and　transmission　at　a　subwavelength　scale.　However,　SPPs　traditionally　suffer　from　large　losses　due　to　the　intrinsic　dissipations　and　absorptions,　which　hinder　further　development　and　applications　of　SPPs.　Here,　we　theoretically　and　experimentally　investigate　the　concept　of　stepped　waveguide　metamaterials　behaving　as　low-loss　effective　replicas　of　SPPs.　The　proposed　structure　without　natural　plasmonic　material　maintains　the　identical　field　configuration　to　that　in　regular　SPP　but　avoids　the　inherent　losses,　outperforming　regular　low-loss　SPP　design　with　natural　plasmonic　materials　on　SPP　propagation　lengths.　Furthermore,　stepped　waveguide　metamaterial　exhibits　excellent　compatibility　in　direct　interconnections　with　arbitrary　regular　SPP　and　potentially　represents　a　feasible　route　toward　new　SPP　devices　with　low-loss　advantages.