Inclusion Criteria:

          1. Diagnosis of active MM as defined by any of following: a) serum M protein more than or
             equal to 10g/dL; b) urine M protein more than or equal to 200mg/24 h; c) involved
             serum free light chain more than or equal to 100mg/dL with abnormal serum kappa lambda
             ratio;

          2. Patients with clear BCMA expression(percent of BCMA positive plasma cells more than or
             equal to 20%) detected by flow cytometry;

          3. High-risk chromosomal abnormal defined as presence of del17p, and/or t(4;14) and/or
             t(14;16);

          4. Estimated life expectancy more than or equal to 3 months;

          5. Absolute neutrophil count more than or equal to 1*10^9/L;

          6. Platelet count more than or equal to 25*10^9/L;

          7. Absolute lymphocyte count more than or equal to 1*10^8/L;

          8. Liver, kidney and cardiopulmonary functions meet the following requirements: a) Total
             bilirubin less than or equal to 2*ULN(except for Gilbert Syndrome); ALT and AST less
             than or equal to 2.5*ULN, maintenance of kidney function not depend on dialysis;
             c)Corrected serum calcium less than or equal to 12.5 mg/dL or free ion calcium less
             than or equal to 6.5mg/dL(1.6mmol/L);

          9. Sufficient venous access for leukapheresis collection and no other contraindications
             to leukapheresis;

         10. Subjects and sexual partner with fertility are willing to use effective and reliable
             method of contraception for at least 1 year after CAR-T infusion;

         11. subjects must have signed writtern informed consent.

        Exclusion Criteria:

          1. Accompanied by other unctrolled maligancies. Two exceptions to this criteria: Recepted
             radical therapy carcinoma without activity within 3 years before screening; fully
             treated skin non-melanoma;

          2. Any situations not benefit for subjects to accept or tolerated to planned therapy or
             understand informed consent; or any situation in which investigators believe that
             participation in this study is not in the subject's best intreat(eg., harm to health),
             or any situation that may prevent, limit or confuse the assessment;

          3. Convulsion or stoke within past 6 months;

          4. Any instability or systemic disease within 6 months prior to screening, including but
             not limited to congestive heart failure(New York heart association classification ≥
             III)， unstable angina, cerebrovascular accident, or transient cerebral ischemic,
             myocardial infarction, LEVF<50%(assessed by an echocardiogram or multi-door circuit
             scan);

          5. Patients have central nervous system(CNS) metastases or CNS involvement(including
             cranial neuropathies or mass lesions and leptomeningeal disease);

          6. Subjects with positive HBsAg or HBcAb positive and peripheal blood HBV-DNA titer is
             higher than the lower limit of detection of the research institution; HCV antibody
             positive; HIV antibody positive; syphilis primary screening antibody positive;

          7. Presence or suspicious of fungi, bacteria, viruses or other infections that are
             uncontrollable or requiring intravenous treatment;

          8. Activity of autoimmune disease (such as crohn's disease, rheumatoid arthritis,
             systemic lupus erythematosus), orhistory of autoimmune disease within the last 3
             years;

          9. Clinical evidence of dementia or changes of mental state;

         10. Exist of pulmonary fibrosis;

         11. Allergy subjects or history of severe hypersensitivity;

         12. Oxgen inhalation requirement to maintain adequate oxygen saturation;

         13. Surgery (except for local anesthesia surgery) plan 2 weeks before apheresis, during or
             2 weeks after CAR-T infusion;

         14. Patients who are accounted to be not appropriate for this investigator.