The genetic transformation system of cucumber ‘New Jinchun 4’ mediated by Agrobacterium tumefaciens were studied. The cucumber leaves as explants were pre-cultured on MS + 1.0 mg L-1 6-BA + 0.15 mg L-1 IAA for 2 days. After infected by Agrobacterium (OD600=0.8, pH=5.7) for 8 min supplemented with 150 μmol/L acetosyringone (AS), the explants were co-cultured on MS + 1.0 mg L-1 6-BA + 0.15 mg L-1 IAA + 500 mg L-1 Carb + 40 mg L-1 Hyg for 2 days. The hpt gene were transformed successfully to regenerated plantlets by gus instantaneous expression and PCR test.