In this article, a low loss circular photonic crystal fiber (C-PCF) has been suggested as Terahertz (THz) waveguide. Both the core and cladding vicinity of the suggested PCF are constituted by circular-shaped air holes. The optical properties such as effective material loss, effective area, core power fraction and V-parameter have numerically been probed by utilizing full vectorial finite element method (FEM) with perfectly matched layers (FMLs) boundary condition. The reported PCF reveals low absorption loss and large effective area of 0.04 cm⁻¹ and 2.80×10⁻⁰⁷ m² respectively at 1 THz operating frequency. In addition, the core power fraction of the fiber is about 50.83 % at the same activation frequency. The V-parameter shows that the proposed PCF acts as a single mode over 0.70 to 1.15 THz frequency. So, the reported PCF offers the best performance in long distance communication applications.