Abstract: Using Maxwell(s equations and the linear theory, the dispersion equations of wave propagation along the waveguide filled with radially and inhomogeneously unmagnetized plasma are deduced in this paper. Its propagation characteristics are discussed. The wave dispersion curves under radially linear and parabola plasma distribution are calculated quantitatively. The principles of variation compared with homogeneous conditions are discovered:the cut-off frequencies of HE waves decrease, while the cut-off frequencies of EH waves increase.