Abstract: The injury of vascular endothelium,activation of coagulation and exist of fibrinolysis in patients with acute leukemia caused the coagulation disorders.It would appear hypercoagulation status or thrombosis,and the incidence was about 10 %- 40 %.It appeared in the early phase of this disease,chemotherapy or infection,and may have no clinical symptoms or signs.The routine coagulation index was also very difficult to detect this hyper coagulation state.Therefore,monitoring in different phrase the content of plasma AT-Ⅲ,vWF and DD in acute leukemia provided the evidence for early diagnosis,prevention and cure of acute leukemia.