Cancer gene therapy is the transfer of genetic material to the cells of host with the goal of eradicating cancer cells,both in the primary tumor and metastases. Therapeutic agents in cancer gene therapy are delivered to the tumor cell using a carrier that might be either a nonviral vector or,the more efficient at gene delivery to target cells,a viral vector. It contains adenoviral vectors,adeno-associated virus vectors,retroviral vectors and herpes viral vectors,which have been widely used in basic research and clinical trials.