Treatment planning of carbon-ion radiotherapy (C-ion RT) should best use the physical and biological advantages of the radiation, which is heavily coupled to the beam delivery system. In this section, overview of conventional system for broad-beam delivery, which has been used for many years, and a state-of-the-art system for pencil-beam scanning are described in addition to general aspects to plan a treatment of carbon ion radiotherapy. Finally, we demonstrate the comparison between broad and scanning-beam plans for a few cases.