Objective:To explore the rehabilitations effect of hyperbaric oxygen(HBO)treatment on extremities trauma.Methods:In this series,486 extremities injured in traffic accidents were treated with HBO and 256 cases without as controls.Medium molecule substances in plasma of the patients were measured before and after HBO treatment.Animal experiments on the healing effects with HBO treatment were conducted.Results:HBO treatment significantly raised the survival rate in digital replantation,skin transplantation,flap transfer and promoted the fracture healing.The wound healing in HBO treatment group was superior to control one.The medium molecule substance content tended towards a normal scale after HBO treatment,while the content increased substantially in control group.Conclusions:HBO treatment can promote the healing rate of fractures extremities and survival rate of digital replantation,skin transplantation,and flap transfer.The changes of the medium molecules substance content are closely related to the severity of the trauma.