Objective To analyze the clinical characteristics of children infecting with Epstein -Barr virus. And in purpose to improve the knowledge of children infecting with Epstein -Barr virus.Methods We analyzed retrospectively to 97 cases of children which serodiagnosis of Epstein -Barr virus infectius in the aspects of the onset season,the age,clinical characteristics.And compared with complication group and no complication group in the aspects of the white cell count,neutrophils to white cell count ratio,lymphocyte to white cell count ratio and C -reactive protein.And contrasted the presence of statistical difference.Results The peak months were spring and summer(58 cases);Pre -school age was the peak age of EBV infectious(41 cases),and the rest respectively were toddlers age(33 cases),school age and youth(20 cases)and infant period(3 cases).The most frequently clinical manifestation respectively was pharyngitis,and other such as fever,lymphadenopathy,hepatosplenomegaly.There had no statistical difference in the two groups of complication group and no complication group in the aspects of the white cell count,neutrophils to white cell count ratio,lymphocyte to white cell count ratio and C -reactive protein(P >0.05).Conclusion The infant can suffer from infectious mononucleosis infect with EBV.Infectious mononucleosis have a variety of clinical manifestation,which always have some complications.The diognosis should combinate clini-cal manifestation with laberatory test.