Abstract: Following small molecules and monoclonal antibodies, oligonucleotides are expected to overcome the rare and refractory human diseases. It has been attracted the attention of the pharmaceutical industry since the approval of six oligonucleotides in recent years because of their unique mechanism of regulating disease gene transcription at the RNA level. As a new class of drug molecules, oligonucleotides are highly polar, charged, and need to be improved by means of chemical modification and drug delivery systems. And therefore, they have different clinical pharmacology properties compared with chemical molecules and monoclonal antibodies, which pose new challenges for early clinical development. This paper reviews the characteristics of oligonucleotides from the perspective of technological development, mechanism of action, human pharmacokinetics, efficacy and safety.