Antisense technique, developed on the principle of base complementation, is a method using short strand oligonucleotide fragments complementary to target DNAs or target RANs for inhibition of gene expression. As a theoretically perfect and specific method to block the expression of gene, it has been rapidly developed over the last twenty years. This review expatiates on its techniques, its problem and possible way of problem-solving, and its recent application in medicine. Also this review discusses the trends of its further development.