The neuromyelitis optica spectrum disorders (NMOSD) are a spectrum of central nervous system autoimmune diseases caused by humoralmediated immunity. NMOSD is characterized by specific expression of aquaporin-4 (AQP-4) antibody and involvement of optic nerve and spinal cord.  However, the expression level of AQP-4 antibody is not directly proportional to disease activity and recurrence rate, suggesting that multiple mechanisms  have been involved in mediating the process of disease. Many evidences of clinical and basic experiments indicated that B lymphocytes play an important  role in the pathogenesis of NMOSD. This paper mainly summarized the role of B lymphocytes in the pathogenesis of NMOSD, including aspects of antigen presentation, humoral immunity, regulatory B cell effect and B cell immune tolerance.