An optical fiber with novel waveguiding mechanism is proposed. The proposed fiber consists of a circularly-arranged array of high index rods and low index cladding and core region. The wave is confined in the inner region surrounded by the rods by guided-mode reso- nance (GMR). Different from the conventional circular fibers in which wave is confined by total internal reflection, the proposed fiber exhibit relatively narrow guiding condition due to its GMR- confinement. Some of the optical characteristics such as dispersion relations, mode field profiles, and loss spectra are analyzed using Finite-Difference Time-Domain (FDTD) method.