Abstract: Based on the monetary approach to balance of payments theory, this paper deduces a model of global imbalances under the condition that a sovereign currency acts as the international reserve currency. This model analyzes global imbalances from the aspect of export-oriented strategy, fear of floating, international dollar reserves and dollar circumfluence. This model hopes to explain the phenomenon that global imbalances begin to be aggravated from the early of 1990s although the demand of rest of world for dollars has always been there. This article divides the countries around the world into the reserve currency countries and the non-reserve currency countries. Due to the fear of floating, the non-reserve currency countries tend to adopt the actually fixed exchange rate to the reserve currency countries. In this situation, if the non-reserve currency countries hope to promote economic growth through export-oriented strategy, the condition would be that credits or international reserves grow continuously in the non-reserve currency countries. After the several financial crises during the 1980s, more and more countries are no longer taking the method of increasing domestic credit and adopt the way of accumulation of international reserves to boost economic growth, and this led to the more and more amounts of international reserves in the non-reserve currency countries. At the same time, according to relationship of correspondence between the reserve currency countries and the non-reserve currency countries, the reserve currency countries will produce current account deficit. The international reserves in the non-reserve currency countries flow back to the reserve currency countries through the capital and financial account, thus the reserve currency countries gradually accumulate a large number of foreign debts. This situation runs continuously and global imbalances are aggravated.