Abstract: The effect of Kanamycin (Kan) and Cefotaxime (Cef) with different concentrations on adventitious bud differentiation from leaflets of Petunia hybride and rooting of the tube plantlets was studied by taking 4 cultivars, namely ‘Meishengchenguang’, ‘Huangjinrouhong’,‘Shanhuhong’ and ‘Huangjinziluolanxingtiao’ as experimental materials. The appropriate antibiotic concentrations were screened. The results showed that 30mg/L Kan could restrain adventitious bud differentiation, and no adventitious buds occurred when the concentration of Kan was 50mg/L.Similarly, low concentration of Kan restrained the rooting of tube plantlets, while no adventitious roots took place when Kan concentration was 30mg/L. The occurrence of adventitious buds were limited under the condition of 550mg/L Cef, and 400mg/L Cef was the suitable concentration for adventitious bud differentiation.