Progress of molecular biological technology has brought about great advances in gene therapy. The establishment of DNA recombination and transfection techniques in 1980s allowed us to utilize gene as therapeutics. Since the initial clinical trial of gene therapy in 1990, over 250 of clinical protocols have been undergone in United States and over two thousand patients have been enrolled in gene therapy in worldwide. First gene therapy protocol was carried out in 1995 and cancer gene therapy was just started last year in our country. The overview of gene therapy in this quarter century was described and also the development of gene therapy related technologies was mentioned in this review.