In this article, a general full-wave two dimensional finite difference frequency domain (2D-FDFD) method is presented that could be used to analyze general circular multi-layered multi-conductor guiding structures. The FDFD method is mainly used to get the dispersion curves for these structures. The results which are obtained using the FDFD equations come through solving an eigen-value problem, where the obtained eigen-values and eigen-vectors are used to produce the propagation constants, distribution of the fields and the characteristic impedances for these structures. Several examples ranging from simple coaxial lines to coupled circular microstrip lines are presented. The FDFD results are compared with those obtained through other analytical and numerical techniques.