The disease can be transmitted to adults, and although it is mainly seen in children and adolescents, adults are also at risk of infection. It is mainly transmitted orally, and patients and EBV carriers are the main sources of infection. Its clinical manifestations include fever, enlarged lymph nodes, pharyngitis, hepatosplenomegaly, and rash. The main test results suggest an increase in heterogeneous lymphocytes, which can be up to 10% or more, and a positive serological test for anti-shell antigen IgM, which is definitive evidence for the diagnosis of EBV infection. Antiviral therapy and symptomatic treatment are needed. There is no obvious specific drug for antiviral therapy, but early application of ganciclovir is effective, and if bacterial infection is combined, penicillin can be given for symptomatic treatment.