AbstractA new type single mirror polarizing system is proposed for Electron cyclotron current drive (ECCD) in toroidal plasma. A single deep grooved mirror (DGM) can generate suitable elliptical polarizations for both of ordinary mode (O-mode) and extraordinary mode (X-mode) in oblique launch with a slanted magnetic field line. Estimated mode purity of O and X modes on the plasma surface is higher than 90% for almost all ECCD experimental condition.