Abstract: When using the finitedifference timedomain (FDTD) method to solve the electromagnetic problems, the locally conformal grids are often chosen to conform the shape of the boundary such as a curved or slant plane. Pentagonal conformal grids modeling in the twodimensional cylindrical coordinate are specially discussed in this paper. This model is available not only to the perfectly electrically conducting boundary but also to the more complex structures such as the slant thin material sheets and the uneven specific conductance slant materials. The reflection from the pec conical antenna and the farzone radiated waveform from the resistiveloaded conical antenna are taken as examples to validate the effectiveness of the modeling, and the results are good.