Symmetric tapered dielectric structures in metal have demonstrated applications such as the nanofocusing of surface plasmon polaritons,as well as the waveguiding of V-channel polaritons.Yet the fabrication of smooth-surfaced tapered structure remains an obstacle to most researchers.We have successfully developed a handy method to fabricate metal-sandwiched tapered nanostructures simply with electron beam lithography.Though these structures are slightly different from conventional symmetric V-shaped structures,systematic simulations show that similar functionality of surface plasmon polariton nanofocusing can still be achieved.When parameters are properly selected,wavelengthselective nanofocusing of surface plasmon polaritons can be obtained. Symmetric tapered dielectric structures in metal such as light-emitting diodes handy method to fabricate metal-sandwiched tapered nanostructures simply with electron beam lithography. Though these structures are slightly different from conventional symmetric V-shaped structures, systematic simulations show that similar functionality of surface plasmon polariton nanofocusing can still be achieved. , wavelengthselective nanofocusing of surface plasmon polaritons can be obtained.