Abstract: Objective　To summarize the examination data of 2 cases with thrombotic thrombocytopenic purpura (TTP) in Lanzhou University Second Hospital. Methods　The closely related diagnostic features of TTP were reviewed retrospectively：hemoglobin (Hb)，platelet (PLT)，reticulocyte (RET)，fragments of red blood cell（FRC），urinary protein (PRO)，urinary occult blood (BLD)，lactate dehydrogenase (LDH)，total bilirubin (TBil)，direct bilirubin (DBil)，indirect bilirubin (IBil)，urea nitrogen (BUN)，creatinine (Cr)，D-dimer (D-D) and bone marrow analysis. Results　Intravenous infusing plasma, PLT and immunoglobulin could not improve the severe reducing of PLT. Intravenously infusing red blood cells (RBC), Hb declined progressively. PRO and BLD were persistently positive. RET，TBil，IBil and LDH of hemolysis test continued to rise. D-D of coagulation test continued not to reduce. Bone marrow analysis showed that 2 patients were proliferative anemia and hemolytic anemia with Evans syndrome respectively. Conclusions　Shallow understanding of TTP diagnosis leads to delay the clinical diagnosis and treatment. By retrospectively reviewing the tests and clinical features of TTP， the classic "five signs" are found, including thrombocytopenia，microangiopathic hemolytic anemia,neurologic symptoms，renal damage and fever.

Key words: Thrombotic thrombocytopenic purpura, Retrospective analysis laboratory test, Diagnosis and treatment improvement