High quality High-κ dielectrics on graphene were achieved by atomic layer deposition directly using remote oxygen plasma surface pretreatment. The uniform coverage on graphene is illustrated by atomic force microscopy and confirmed by high resolution transmission microscopy. The possible surface lattice damage induced by plasma is limited and demonstrated by Raman spectra. The excellent Hall mobility for graphene is maintained at 2.7 × 103 cm2/V.s, which only decreases by 25%. The excellent electrical characteristic of dielectric presents the low leakage current density and high breakdown voltage. Moreover, the technology is compatible with the traditional CMOS process which brings much possibility to future graphene devices.