Routine blood tests are one of the mandatory tests for rheumatic immune diseases, especially for patients who are first diagnosed and treated, because rheumatic immune diseases are most likely to cause abnormal changes in blood routine, and by checking blood routine, we can generally determine which kind or type of rheumatic immune disease is involved. The following is a brief discussion of the significance of blood routine abnormalities in rheumatic immune diseases. 1, leukopenia: common in systemic lupus erythematosus, dry syndrome, mixed connective tissue disease, autoimmune hepatitis, also seen in rheumatoid arthritis, when rheumatoid arthritis appears leukopenia, neutrophil deficiency, splenomegaly, also known as Felty syndrome. 2, leukocytosis: seen in almost every adult Still’s disease (Still) patients, 75% of patients with leukocytes ≥ 15 × 109 / L, some patients even appear infantile cells and present leukemia-like reaction, while there can be high fever, rash, liver, spleen, lymph node enlargement, etc.. Other rheumatic diseases that can cause a mild increase in leukocytes include rheumatic fever, polymyositis/dermatomyositis, systemic vasculitis including allergic purpura, aortitis, polyarteritis nodosa, leukoaraiosis, allergic granulomatous vasculitis, etc. 3, thrombocytopenia: common in systemic lupus erythematosus, systemic lupus erythematosus with thrombocytopenia as the first symptom is common, also seen in antiphospholipid antibody syndrome, dry syndrome, overlap syndrome, etc. 4, thrombocytosis: common in rheumatoid arthritis, ankylosing spondylitis, reactive arthritis, etc. 5, anemia: common in SLE, there are many cases of SLE with hemolytic anemia as the first symptom, others are also seen in rheumatoid arthritis, dry syndrome, aortitis, systemic sclerosis, polymyositis/dermatomyositis, etc. Rheumatic immune diseases are caused by environmental factors, sex hormones, infectious factors, immune factors and other factors that lead to autoimmune dysfunction, which in turn produce a large number of immune complexes that destroy oneself and activate the complement system, releasing a large number of inflammatory factors and causing the disease to develop. Therefore, when there are abnormal changes in blood routine, especially accompanied by fever, joint pain, muscle pain, mouth ulcers, dry mouth, dry eyes, skin purpura, skin erythema, weakness, emaciation and other symptoms, we must be alert to rheumatic immune diseases, and should go to the Department of Rheumatology and Immunology for early diagnosis and treatment to achieve clinical cure.