Abstract: A technique of symmetry analysis for modal characteristics in uniform waveguides or resonators with ferrite rods is presented here. Symmetry analysis provides basic imformation coneerning modal characteristics, such as mode classification, mode degeneracies between mode classes, the azimuthal symmetries of the modal electromagnetic fields in each mode class, and specifying minimum waveguide sectors for each mode class which completely determine the modes of that mode class. After summarizaing of the basic points of symmetry analysis, some problems concerning symmetry operations are discussed, especially on modal electromagnetic fields in uniform waveguides containing ferrites. Then the given process of symmetry analysis is applied to the structures, i.e. uniform waveguides with Cn symmetry or Cnv symmetry and resonators with Dnh symmetry in which exist longitudinally magnetized ferriet rods. Finally, the analytical results are given in four tables.