Abstract: Thrombotic thrombocytopenic purpura is a type of thrombotic microangiopathy and it is also a rare disease, which main characteristics including thrombocytopenia,microangiopathic hemolysis,neurological abnormality,renal dysfunction and fever_¹.A 37-year-old man with left great toe skin ulceration who drainaged for 2 weeks and lost consciousness for 1 day was admitted.This patient was finally diagnosis as thrombotic thrombocytopenic purpura with symptoms of convulsions, unconsciousness, laboratory tests including thrombocytopenic, severe increase broken red blood cells in peripheral blood smear (14%), decreased hemoglobin, increased reticulocyte, total bilirubin, indirect bilirubin, lactate dehydrogenase,creatinine and urea nitrogen were increased. This case is relatively rare in clinic. It is easy to miss and misdiagnose. Now we are going to report the clinical diagnosis and treatment of this case and review the relevant literatures to improve the comprehension of this disease and treatments.