The AhDREB1 gene, cloned from Atriplex hortensis L., was transferred into black locust (Robinia pseudoacacia L.) by an Agrobacterium-mediated transformation. The results suggest that stems of black locust sub-cultured in vitro for 20 d are suitable for genetic transformation. The optimum concentrations of kanamycin and cefotaxime were 30 and 150 mg·L-1, respectively. Impor-tant factors affecting the transformation efficiency were studied by means of a L9(34) orthogonal design. An effective system for ge-netic transformation in black locust was developed as follows: the stems were pre-cultured for 2 d, immersed in the Agrobacterium solution (OD600 = 0.7) with 10 mg·L-1 acetosyringone for 21 min and then co-cultured for 2 d. The selection pressures, changing from low to high, could improve transformation efficiency. The transgenic plants were identified by a PCR method. The PCR results indicated that the AhDREB1 gene had been integrated into the genome of black locust and two lines of the transgenic plants were obtained. The AhDREB1 gene, cloned from Atriplex hortensis L., was transferred into black locust (Robinia pseudoacacia L.) by an Agrobacterium-mediated transformation. The results suggest that stems of black locust sub-cultured in vitro for 20 d are suitable for genetic transformation . The optimum concentrations of kanamycin and cefotaxime were 30 and 150 mg · L-1, respectively. Impor-tant factors affecting the transformation efficiency were studied by a L9 (34) orthogonal design. An effective system for ge-netic transformation in Black locust was developed as follows: the stems were pre-cultured for 2 d, immersed in the Agrobacterium solution (OD600 = 0.7) with 10 mg · L-1 acetosyringone for 21 min and then co-cultured for 2 d. The selection , changing from low to high, could improve transformation efficiency. The PCR plants indicated that the AhDREB1 gene had been integrated into the genome of black locust and two lines of the transgenic plants were obtained.