Several clinical studies have shown that rituximab is safe and effective for the induction of remission in moderate to severe systemic lupus erythematosus, and has been recommended by several guidelines for the induction of remission in refractory lupus with important organ involvement. However, there are few studies on the use of rituximab in the long-term maintenance and remission of the disease. There is no recognized scheme for the dose, interval and course of treatment of the drug. In this study, patients with moderate and severe systemic lupus erythematosus who achieved remission after standardized treatment were randomly divided into two groups at 1:1 and followed up every 3 months for 24 months. The basic situation and disease activity score of each subject were recorded. The recurrence rate of each observation group was calculated, the influencing factors of disease recurrence were analyzed, and a more reasonable drug use scheme was explored.

Inclusion Criteria:

1. Age, 18-65 years old, weight ≥ 40 kg, sex unlimited.
2. Clearly diagnosed with systemic lupus erythematosus.
3. There was at least one BILAG B or above score in the kidney, blood system and nervous system.
4. After standardized treatment with high dose glucocorticoid combined with immunosuppressants such as CTX,MMF or RTX, complete or partial remission of the disease was achieved (up to 1 BILAG B score, and at least 1 BILAG A or BILAG B score less than before).
5. Glucocorticoid: prednisone or the equivalent of prednisone less than or equal to 20 mg daily dose, and can be increased or decreased within 20 mg during the study.
6. Subjects are willing to participate in this study and sign informed consent voluntarily.
7. Prospective subjects agreed to use effective contraception throughout the study period.

Exclusion Criteria:

1. Abnormal liver function: ALT or AST >2ULN，or ALP or TBil >1.5ULN
2. Severe cardiopulmonary disease;
3. Severe blood system disease
4. Patient with malignant tumor;
5. Concurrent infection：Subjects were hospitalized for infection or treated with parenteral antibiotics within 30 days before random; Hepatitis B surface antigen positive or active hepatitis, not treated with hepatitis B antivirus; T-SPOT positive or active tuberculosis, not treated with antituberculous therapy; Any positive in HCV-Ab, HIV-Ab, or TPPA ;
6. Pregnant patients or patients with recent fertility requirements;
7. Received cyclophosphamide treatment within 30 days before random;
8. For any other reason, the investigator believes that it is inappropriate to participate in the trial.