We propose a linearly polarized dielectric resonator antenna (DRA) array, feeding by radial line waveguide, to simplify the traditional feeding structures of the DRA array. By effectively using the electromagnetic wave inside the radial line waveguide, the proposed dielectric resonator antenna array, with only one feeding port, working at 12GHz, achieves a directivity of 27.18 dB, a high aperture efficiency of 66.4%, a total efficiency of 62.95% and good linearly polarization properties.