Abstract: Objective:To explore the effects of vidarabine monophosphate in the treatment of infectious mononucleosis(IM) in children.Methods:One hundred and sixty-five children with IM were divided into vidarabine group 92 cases and ganciclovir group 73 cases according to their treatment protocol.The vidarabine group and ganciclovir group were treated with 10 mg/kg of vidarabine through intravenous drip once a day for 10 to 14 days and 10 mg/kg of ganciclovir through intravenous drip once 12 hours for 7 days,then 5 mg/kg once a day for 3 to 7 days,respectively.The fever course of acute phase,isthmopyra improvement time,hepatic and splenic lymph node retraction time and atypical lymphocyte recovery time in two groups were observed.The curative effects of two groups were analysed.Results:The differences of the fever course of acute phase,isthmopyra improvement time,hepatic and splenic lymph node retraction time and atypical lymphocyte recovery time between two groups were not statistical significances(P0.05).The difference of curative effect between two groups was not statistical significances(P0.05).Conclusions:The effect of vidarabine monophosphate in the treatment of IM in children is similar to ganciclovir.