Abstract:An efficient in vitro plant regeneration system of Cucumis melo L. cv. Hetau was established. Regenerated plantlets were obtained from cotyledons after preculture, shoot inducing culture and root inducing culture. A high regeneration rate was achieved up to 58%. Cucumis melo was transformed with the antisense tomato ACC synthase gene in binary vector pMQ6 via Agrobacterium tumefaciens mediated gene transfer. Kanamycin resistant plantlets were obtained on MS medium with 6 mg/L zeatin, 50 mg/L kanamycin and 650 mg/L cefotaximine. PCR and molecular hybridization analysis showed that tomato ACC synthase antisense cDNA was integreted into the genome of C. melo.