Abstract: Hematopoietic stem cell transplantation is a pivotal method to treat hematological malignancies, hematopoietic failure diseases and inherited metabolic diseases. Umbilical cord blood is one of the main sources of hematopoietic stem cells and the most ideal cell source for stem cell research and application. In this article, the clinical application of umbilical cord blood transplantation for more than 30 years was reviewed from the aspects of the history, current situation, advantages, improvement, application prospect and expectation of umbilical cord blood transplantation.