The transient gene delivery systems are generally mediated by viral infection,particle bombardment, electroporation, and microinjection for transferringexogenous DNAs into host cells. Recently, the peptide-mediated DNA deliverysystem became a novel tool for gene transfer, and these peptides, such ascell-penetrating peptides (CPPs), contained the ability of permeating plasmamembranes and carrying cargoes to enter cells. In this study, we use threedifferent arginine-rich CPPs, synthetic nona-arginine (SR9), histidine-richnona-arginine (HR9), and Pas nona-arginine (PR9), for gene delivery into root-tipcells of mung bean and rice. We demonstrate that these arginine-rich CPPs havethe ability to transfer Cyanine 3 (Cy3)-labeled DNAs into plant cells. Moreover,the CPP-mediated DNA transfer in cells was confirmed by polymerase chainreaction (PCR) analysis. Finally, our results of the functional gene assay indicatedthat DNA exerts its biological activity after intracellular delivery via CPPs. ThisCPP-mediated gene delivery method is characterized by the simplicity,noninvasion, and efficiency. Three arginine-rich CPPs may be ideal tools for theresearch of plant gene transformation.