Cancer is a leading cause of morbidity and mortality worldwide. In addition to the continued effort into developing new therapeutic agents, researchers have also striven to develop novel delivery systems that can effectively improve the therapeutic efficacy of existing anticancer drugs. In recent years, a variety of nano-sized drug carriers have emerged, including liposomes, polymer-based carriers (e.g. dendrimers and polymeric micelles), carbon nanotubes, silicon dioxide nanoparticles and so on. These systems have demonstrated a number of advantages, such as biocompatibility, adjustable size, improved passive targeting at the tumor sites, and easy of surface functionalization for actively targeting at the tumor sites. Here we provided a detailed review on the recent development of these systems.