Abstract：Callus induced from mature embryos of 3 rice varieties were transformed by Agrobactorium tumefaciens. Transformation efficiency was affected by factors of pre-culture time, density of bacteria, duration for inoculation and co-cultivation. The transformation conditions were optimized with the combination of pre-culture of 4 days, infection in bacterium with OD600 0.7-1.0 for 5-10 minutes., followed by co-culture of 2 days. Plantlets with resistance to hygromycin were regenerated. PCR and PCR-Southern analysis on them confirmed the integration of the LycB be into the rice genome.