Recurrent spontaneous abortion (RSA), defined as three or more consecutive pregnancy losses before 20 weeks of gestation, is difficult to treat in the clinical setting. It affects 1%-5% of women of reproduc-tive age. In the investigations of immunopathogenesis, diagnosis, and treatment of RSA since the late 1980s, it was found that RSA was associated with abnormal mateal local or systemic immune response. The pathogenesis of autoimmune RSA was mainly associated with antiphospholipid antibody (APA), while that of alloimmune RSA was due to the disturbance of mateo-fetal immunological tolerance. Systemic etiological screening process and diagnosis systems of RSA with immune type were developed, and anticardiolipin (ACL or ACA) + anti-β2-GP 1 antibody combining multiple assays for effective diagnosis of RSA with autoimmune type was first established. According to the dynamic monitoring of clinical parameters before and during gestation, low-dose, short-course, and individual immunosuppressive therapy and lymphocyte immunotherapy for RSA with immune type were carried out. The outcomes of the offsprings of patients with RSA were followed up, and the safety and validity of the therapies were confirmed. The research achievement leads to great progress in the diagnosis and treatment of RSA in China.