In order to enhance the understanding of thrombotic thrombocytopenic purpura (TTP), the clinical features, laboratory characteristics, treatment and outcome of 14 patients with TTP were retrospectively analyzed and investigated. The results showed that 7 out of 14 patients with TTP had predisposing factors, such as pregnancy in 4 cases, infection in 3 cases, systemic lupus erythematosus (SLE) in 1 case and hematopoietic stem cell transplantation (HSCT) in 1 case. Fourteen patients all had neuropsychological symptoms, hemolytic anemia with negative-Coombs test, and decreased platelet counts. Eight patients had irregular fever with different degree. There were 8 patients with kidney damage including proteinuria in 8 cases and renal function abnormalities in 4 cases. The von Willebrand factor-cleaving protease (VWF-CP, ADAMTS13) activity of 13 cases out of 14 patients significantly decreased (less than 10%). At same time, plasma ADAMTS13 inhibitors were detected in 12 cases out of these 13 patients with decreased ADAMTS13 activity. After treatment with plasma exchange, glucocorticoid and rituximab so on, 12 cases achieved complete remission, in which 8 cases relapsed in two years. Two patients died at last, in which one case was secondary to HSCT. It is concluded that TTP is a kind of thrombotic microangiopathy due to platelet microthrombosis involved in multiple systems and multiple organs dysfunction with dangerous clinical process. The mortality of TTP patients is very high. Early diagnosis and early treatment with plasma exchange as the main means can greatly improve the prognosis of patients with TTP.