Since maize is one of the most important cereal crops in the world, establishment of an efifcient genetic transformation system is critical for its improvement. In the current study, several elite corn lines were tested for suitability ofAgrobacterium tumefaciens-mediated transformation by using immature embryos as explants. Infection ability and efficiency of transformation ofA. tumefacienssp. strains EHA105 and LBA4404, different heat treatment times of immature embryos before infection, inlfuence of L-cysteine addition in co-cultivation medium after transformation, and how different ways of selection and cultivation inlfuence the efifciency of transformation were compared. Glyphosate-resistant gene2mG2-EPSPS was transformed into several typical maize genotypes including 78599, Zong 31 and BA, under the optimum conditions. Results showed that the hypervirulentAgrobacterium tumefacienssp. strain EHA105 was more infectious than LBA4404. Inclusion of L-cysteine (100 mg L-1) in co-cultivation medium, and heating of the immature embryos for 3 min prior to infection led to a signiifcant increase in the transformation efifciency. Growth in resting medium for 4-10 d and delaying selection was beneifcial to the survival of resistant calli. During induction of germination, adding a high concentration of 6-BA (5 mg L-1) and a low concentration of 2,4-D (0.2 mg L-1) to regeneration medium signiifcantly enhanced germination percentage. Using the optimized transformation procedure, more than 800 transgenic plants were obtained from 78599, Zong 31 and BA. By spraying herbicide glyphosate on leaves of transgenic lines, we identiifed 66 primary glyphosate-resistant plants. The transformation efifciency was 8.2%. PCR and Southern-blot analyses conifrmed the integration of the transgenes in the maize genome.