Lower hybrid current drive (LHCD) on an EAST tokamak double null configuration was studied with the GENRAY/CQL3D code.The simulation results show that the high filed side (HFS) LHCD efficiency is lower than that at the low filed side (LFS) for low electron density discharges.As the electron density increasing,the advantages of HFS LHCD gradually emerge.Lower hybrid wave (LHW) launched from the HFS deposits its energy closer to the plasma center.Increasing toroidal magnetic field intensity can help the propagation of LHW.Increasing plasma pressure of magnetic equilibrium configuration in the sa...