Abstract: The use of marker gene is an efficient method to select and identify transgenic cell,tissues and plantlets.In the light of kanamycin resistance gene widely used in plant genetic transformation,a(syste-)(matic) investigation that contributes to genetic transformation on resistance of several vegetable brassicas is made in this experiment.The tests showed that 5 mg/L kanamycin could completely inhibit regeneration of cotyledon of vegetable brassicas.Kanamycin resistance assay of seedlings suggested the tendency that(cotyledon) yellow rates increase,root and stem length decrease,and fresh weigh decrease with the level of kanamycin improved.This provided a base for genetic transformation of vegetable brassicas and screening of their offspring.