EBV positivity, family history of nasopharyngeal carcinoma, high incidence areas of nasopharyngeal carcinoma, and low body immunity may all be high-risk factors for developing nasopharyngeal carcinoma. Theoretically, if a person is positive for EBV, it only means that the patient has been previously infected with EBV, but there is no definite conclusion whether it is the direct cause of the development of nasopharyngeal cancer. However, clinical practice and scientific studies have shown that a positive person has a much greater chance of developing nasopharyngeal cancer than a negative person. Nasopharyngeal carcinoma is the most common epithelial tumor with EBV infection, and almost 100% of non-keratinizing nasopharyngeal carcinomas have EBV infection. Therefore, EBV serologic testing can aid in the diagnosis when nasopharyngeal carcinoma is to be differentiated from other cancers of the nasopharynx. In addition, when metastatic cancer is found in the lymph nodes of the neck, a positive EBV serologic test indicates that the primary tumor is likely to be nasopharyngeal cancer. If there is no abnormal finding under nasopharyngeal microscopy, but the EBV serology titer is high or antibody test is positive, then regular observation should be made with prevention, and it is recommended to ask a specialist for further examination for early diagnosis and treatment. The virus-specific antigens formed during EBV infection can be distinguished as early antigen (EA), viral capsid antigen (VCA), nuclear-associated tumor antigen (EBNA), and membrane antigen (MA). Detection of the corresponding antibody responses to these antigens can help in the diagnosis and treatment of EBV-related diseases. VCA antigens are highly immunogenic and VCA-IGM can be detected in the serum of patients initially infected with EBV, after which the IGM antibodies gradually decrease to undetectable levels (normally, IgM antibodies persist for no more than 10 weeks. The titer decreases and sometimes ebbs and flows. A chronic course of any acute infection is rare), almost simultaneously with a gradual increase in VCA-IGG, and can be present throughout life in normal individuals. If this test is negative, EBV infection can be ruled out. EBNA can be divided into six species, of which EBNA1 is the only viral protein expressed in all EBV-associated tumor cells and appears in the nuclei of all persistently infected cells, with relatively late immunogenic expression, forming anti-EBNA-1 antibodies only weeks or months later. An apparently positive test result (second titer stage) indicates a previous infection. A positive VCA test with a titer of 1:160 or higher, combined with a negative or weakly positive anti-EBNA-1 test, indicates an acute, new or recurrent infection. EA are antigens produced early by infected cells and are less immunogenic than VCA, so they induce antibodies that appear later in primary infections, however, in recurrent infections antibodies are usually detected early. Nasopharyngeal cancer stimulates the synthesis of IgA-like EBV antibodies, particularly anti-VCA antibodies. VCA-IgM is usually negative and VCA-IgG titers are increased. The specificity of IGA/VCA for the diagnosis of nasopharyngeal carcinoma has been proven over the years to be lower than that of IGA/EA, but the latter is less sensitive. In addition to IGA, specific non-structural antigens in the early EBV replication cycle – DNA polypeptidase, DNA nuclease, and DNA major binding protein – are also recommended as serological diagnostic indicators. Clinical significance of EBV-VCA antibodies: VCA-IgA ≥ 1:10 is positive, indicating an EBV infection (mostly six months or a long time ago), clinically associated with nasopharyngeal cancer, thymic lymphoepithelial cancer, gastric cancer, rectal cancer, rheumatoid arthritis, non-A non-B hepatitis, erythema scarum, desiccation syndrome, Burkitt’s lymphoma, lymphoma in immunodeficient hosts, and other diseases . VCA-IgM ≥ 1:5 is positive, indicating a recent infection, (after infection mostly in 2-3 weeks the antibody is elevated, in vivo duration varies) clinically associated with unexplained hair, weakness, infectious mononucleosis, purpura, tamponade, Kawasaki teratology, oral desquamation and other autoimmune diseases; VCA -IgG ≥ 1:80 or more indicates that EBV is activated or activates other viral genes and certain cellular genes, and can be used as a reference tender for EBV or other viral infections.