OBJECTIVE: To evaluate the therapeutic effect on children with acute idiopathic thrombocytopenic purpura (AITP) by intravenous immunoglobulin (IVIG) or dexmethasone (DEX). METHODS: Fortysix patients aged from 4 months to 14 years with AITP were randomized to receive IVIG or DEX, and we monitored the platelet count (Tc) and observed the side effects after each treatment. RESULTS: There was no difference in the lasting time of Tc≤20×109/L and the time when Tc increased to ≥50×109/L between the treatment of IVIG and DEX (P>0.05). But the percentage of patients with Tc≥50×109/L was higher in the IVIG group Ⅱ (88%) than in the DEX group (50%) after the 5 day treatment (P<0.05). CONCLUSIONS: We may choose IVIG to treat the patients with AITP complicated by severe mucomenbrane and organ bleeding, while we may use DEX if the patients have no complication.