The genomic information obtained through the human genome project has been accelerating the analysis of the functions of various disease relevant genes. The high molecular weight biomolecules becomes increasingly important for the development of molecular therapies. However, the usage of such therapeutic macromolecules has been limited by the poor permeability across the lipid bilayer of the cellular plasma membrane. In order to overcome this barrier, several chemical and physical methods have been developed, such as electroporation and cationic lipids/liposomes. The drawbacks of these methods are the unwanted cellular effects and their limitation to in vitro applications. Cell penetrating peptides (CPPs) is a group of oligopeptides that could penetrate the cell membrane via a receptor-independent and non-endocytotic process with various conjungated bioactive molecules. Such ability makes them outstanding transmembrane vectors for various therapuetic biomolecules. In this review, we will introduce several representative strategies to develop antitumor macromolecules using CPPs.