Rituximab is a human/mouse chimeric monoclonal antibody against CD20 antigen of B cells.It is one of the earliest monoclonal antibodies successfully used in the treatment of malignant tumors.In recent years,a number of studies have shown that rituximab can induce apoptosis of CD20-expressing B lymphocytes through antibody-dependent cytotoxicity,complement-dependent cytotoxicity and direct apoptosis induction.Combined with chemotherapy,rituximab can significantly enhance the therapeutic effect on aggressive lymphoma.In addition,rituximab is also play an increasingly important role in the treatment of primary immune thrombocytopenia,autoimmune hemolytic anemia and other autoimmune diseases,neuromyelitis optica,and lymphocytic proliferative diseases after stem cell transplantation.