Abstract: To investigate the clinical symptoms,laboratory examination and molecular marker examination of chronic neutrophils (CNL) with IgD-lambda type multiple myeloma (MM) and to improve the understanding of myeloma and reduce the missed diagnosis,we prospectively reviewed the clinical and pathological data of a patient with CNL with IgD-lambda MM.The clinical symptoms of MICM and monoclonal antibodies were diagnosed in MM,while peripheral neutrophils were significantly increased,the spleen was slightly enlarged,neutrophil alkaline phosphatase integral increased,no Ph chromosome and BCR/ABL fusion gene,JAK2 V617F had no special changes,positive detection of CSF3R gene,and infection and other factors led to reactive neutrality.The bone marrow and clinical manifestations of granulocytosis were consistent with CNL and MM.CNL is extremely rare in myeloid proliferative diseases.Only 8 cases of CNL combined with plasma cell tumors have been reported in China.