Abstract: Objective To evaluate the clinical effect of high-dose Dexamethasone as a initial- and re-treatment of adult patients with primary immune thrombocytopenia （ITP）. Methods We searched the electronic databases for the research of high-dose Dexamethasone as a treatment of patients with primary immune thrombocytopenia.All eligible literatures were assessed for quality.All data were performed by meta-analysis results.The deadline of the retrieval was December 2012.Rusults Thirteen studies involving 558 patients were included.The results of meta-analysis showed that the ORR of naive patients was 82.2%（95%CI 78.1%~85.7%）, the CR was 65.5%（95%CI 58.9%~71.6%）; the ORR of retreatment patients was 52.4%（95%CI 43.1%~61.4%）, the CR was 28.8%（95%CI 21.2%~37.8%）. Conclusion Initial patients may benefit from high doses of Dexamethasone, participating in its advantages of being accessible, and with few side effects.But the result of reteatment patients was not so good.