ObjectiveTo analyze the etiology and clinical characteristics of infectious mononucleosislike syndrome(IMLS).MethodsEightyseven children with IMLS in a hospital from January 2006 to September 2013 were performed pathogenic detection, then clinical features were summarized and analyzed. ResultsThe top 5 pathogens in IMLS were Mycoplasma pneumoniae (MP, n=20 ), cytomegalovirus (CMV, n=13), simplex herpes virus(HSV,n=11), Chlamydia (CP,n=11),and parvovirus B19 (Hpv B19,n=9 ), clinical manifestations of all kinds of diseases were similar, but the occurrence rates were slightly different. MP infection were mainly fever, hepatosplenomegaly, and lymphadenopathy, and most were associated with respiratory complications(including laryngitis,bronchitis,and pneumonia), CMV infection were also showed fever and hepatosplenomegaly, but the latter was more obvious; rubella patients didn’t appear skin rash, but the other symptoms were obvious. ConclusionEtiologies of infectious mononucleosislike syndrome are varied, MP infection is most common, the next is CMV. Pathogens should be ascertained to provide theoretical basis of treatment.