The global current account imbalance exacerbated in the early of 2010s，which contributed to the burst of global financial crisis. Although the global imbalance was significantly corrected after the crisis，there are still uncertainties about its evolution in the future. From the perspective of saving investment gap，the root of global imbalance lies in the decline of saving rates in deficit countries，and the rise of saving rates in surplus countries. From the perspective of real effective exchange rate，the root of global imbalance lies in the overvaluation of deficit countries’ currencies and undervaluation of surplus countries’ currencies. To rebalance global current account，the major countries should try to mitigate the saving investment gap，and move the real effective exchange rates toward equilibrium levels. In the process of global rebalancing，the major countries should enhance communication and cooperation and avoid exchange rate wars and trade wars.