Current drive via non-resonant interaction between RF waves and plasma is studied by using kinetic wave analysis and computation in a stationary state. The non-resonant interaction generates a force, in addition to the usual ponderomotive force. The force under consideration mainly acts as an internal force among plasma species; the net momentum input from the wave to the plasma is small in this process. The current driven by this process is not included in the conventional current drive scheme (i.e. resonant absorption of the parallel wave momentum or wave energy) and appears to be associated with the change in the RF wave helicity 〈A·B〉. The analysis is applied to ICRF waves in large tokamaks. A one-dimensional wave analysis code (TASK/W1) shows that the conversion ratio of the RF wave helicity to the DC helicity becomes close to one in the case of hot plasmas. The current drive efficiency of RF helicity injection is not necessarily bounded by the conventional RF current drive efficiency. A preliminary study suggests that it scales strongly with electron temperature and toroidal magnetic field but only weakly with plasma density.