We present a new type of aperture antenna with V-groove structures that are made of Au to enhance strong circularly polarized light (CPL). Simulations using the finite element method revealed that strong CPL was enhanced within the aperture with a diameter of 10 nm. The intensity of the electric field was enhanced and was 22,700 times greater than that of the incident light. The channel plasmon polaritons generated in the V-groove structures were responsible for the strong enhancement. The influence of the angle and length of the V-groove on the enhancement of the CPL was investigated.