Fujian Medical University Union Hospital is conducting a multicentered, phase 4, randomized controlled study looking at the effectiveness of two different dosing regimens of intravenous immune globulin (IVIG) in the treatment of children with newly diagnosed immune thrombocytopenia. Eligibility is restricted to those who are between the ages of 29 days to 14 years of age who have primary ITP and have not been treated for their ITP. Participants must also have a platelet count less than 20,000 µL. Participants will be excluded if they had any serious internal organ bleeding requiring emergency treatment in the last six months. ITP participants who are female and have started menses (menstruation) will also be excluded from participating.