Gene therapy aims to (1) introduce specific genes into a host to replace defective ones (replacement therapy); (2) suppress expression of certain undesirable genes (antisense therapy); or (3) provide additional biological activities (supplement therapy). Naked DNA and viral or non-viral vectors containing candidate genes for human gene therapy are being actively pursued by researchers in molecular medicine. New gene transfer technologies are rapidly developing and some have proved to be powerful tools for medical research. This review discusses the development and application of particle-mediated gene transfer technology in experimental systems and its potential clinical utilities.