It is usually recognized that a considerable amount of heating power additional to the ohmic heating will be required to reach ignition in a tokamak reactor. To this purpose, we use the method of the injection of wave. In the large tokamaks, poloidal magnetic field is ignorable versus toroidal magnetic field. Since toroidal magnetic field is very large, we can use cyclotron waves to heat plasma. In recent years there has been considerable interest in generating steady-state currents in a plasma with rf waves. In particular, it was predicted that these currents could be efficiently generated by waves whose phase velocities are several times the electron thermal speed. This prediction has been confirmed by numerous experiments in which the current was driven by lower-hybrid waves. The Lower Hybrid is the combination ion and electron cyclotron frequency resonance with wave frequencies in the 1 GHz to 8 GHz range. These results allow us to contemplate a steady-state tokamak reactor in which the toroidal current is driven by lower-hybrid waves. Current drive refers to the production of toroidal electric in a plasma torus that is, current that encircles the torus hole. The intended use of this current is to enable a tokamak fusion reactor to operate continuously. The method known as Lower Hybrid Current Drive (LHCD) provides waves with a hybrid frequency that, although it possesses an inefficient heating effect, it can drive electric current thanks to the fact that it has an electric component parallel to magnetic field lines. The power provided by this method is around 10MW, and is one of the most used methods in the control of the plasma during the fusion process. The lower hybrid wave may transfer its energy to electrons by Landau damping, leading to acceleration of the electrons motion at the direction along with the wave vector, additional electrical current is thus driven. For LH waves, momentum is transferred from the wave to the fast electrons in the plasma at the resonance condition. This process is studied by numerically solving the Fokker-Planck equation with an added quasi-linear term, to solve this equation, take the plasma then to be azimuthally symmetric about the magnetic field and homogeneous, the Fokker-planck equation then reduces to an equation in time and two velocity dimensions. We have used LSC code to solve the Fokker-Planck equation and simulate the lower hybrid waves injected. The Lower hybrid Simulation Code (LSC) is a computational model of lower hybrid current drive in the presence of an electric field. Heating of electrons and ions is also computed. Details of geometry, plasma profiles and circuit equations are treated. Two-dimensional velocity space effects are approximated in a one-dimensional Fokker-Planck treatment. In this project, simulation of injected lower hybrid waves for NSTX, MAST, PLT and TFTR tokamaks have been performed. The results of this project show that spherical torus have better performance than torque tokamaks. This condition causes the fusion reaction self-sustaining realized, should be better than the possibility of nuclear fusion power and performance is provided. Key Words: Lower hybrid waves (LH), Fokker-Planck equation, LSC code, NSTX,MAST,TFTR and PLT tokamaks.