Immunoglobulin and complement can detect the immune status of the body, which can provide diagnostic clues for autoimmune diseases, liver diseases, kidney diseases and many other diseases. Immunoglobulin includes lgA, lgG, lgE, lgD, lgM, each immunoglobulin has different immune ability, and complement is a kind of protein with enzyme activity in human body, including C1, C2, C3, C4, C5 and other kinds of proteins, of which the main test is for C3 and C4, and the abnormality of immunoglobulin is mainly indicative of the patient’s possible existence of immune system diseases or infectious diseases. Abnormal complement C3 test results are associated with kidney disease, liver disease, acute inflammatory injury and other diseases, while abnormal complement C4 test results can be seen in nephritis and autoimmune diseases caused by various immune complexes. It is recommended that patients who have questions about immunoglobulin and complement tests should go to the Department of Rheumatology and Immunology of regular hospitals for detailed consultation.