Plasma heating of a Tokamak plasma by wave coupling in the ion cyclotron range of frequency has been investigated during the last decade along several schemes: in a two-ion plasma containing comparable amounts of the ion components, wave conversion heating is expected to couple the main part of the power to the electrons. For a small fraction of one of the two components, the power will be coupled by minority heating to the low density ion species. Heating of a single ion plasma requires power coupling at the second harmonic frequency. The theoretical basis for those three mechanisms is qualitatively reviewed. Wave conversion heating has been particularly investigated in the TFR Tokamak. The experimental results are reviewed underlining the important role played by metallic impurities on the evolution of ion and electron temperatures and the severe limitation on electron temperature observed in all conditions.