Undifferentiated connective tissue disease (UCTD) has some of the clinical features of autoimmune connective tissue disease, but does not meet the diagnostic criteria for any one specific disease. It may belong to the early stages of one of the diffuse connective tissue diseases or to the tonoplast type, or in some patients it may be a separate disease. To date, no characteristic clinical manifestations or specific laboratory indicators have been found for UCTD. the diagnosis of UCTD mainly relies on the clinical experience of rheumatologists. patients with UCTD often have mild organ damage and are generally treated symptomatically. The treatment plan and drug dosage should pay attention to the principle of individualization and observe the adverse drug reactions. Yu Likai, Department of Rheumatology and Immunology, Wuhan Union Medical College Hospital