Currency exchange can be divided into three levels: one is non-convertible, the other is convertible under current account of balance of payments, and the third is fully convertible, that is, both current account and capital account are freely convertible. The definition of currency convertibility by the International Monetary Fund (IMF) defines convertibility under the current account as the lowest level of convertibility. Article 8 of the Agreement of the International Monetary Fund stipulates the specific requirements for convertibility under the current account, which can be summarized as follows: First, without the consent of the International Monetary Fund, member countries (or regions) cannot impose restrictions on international current payments and capital transfers; Second, it is forbidden to implement discriminatory monetary measures and various exchange rate measures; Third, any member country has the obligation to redeem the domestic currency balance under the current account held by other member countries, that is, to exchange the domestic currency held by foreign countries. Convertibility under capital account requires the abolition of various convertibility restrictions on foreign exchange receipts and payments by short-term financial capital, direct investment and securities investment, so that capital can freely enter and leave the country. In practice, some international reserve currencies still impose some necessary restrictions on capital account convertibility in the process of internationalization. The International Monetary Fund does not give a strict definition of convertibility under capital account. The ultimate goal of China's foreign exchange system reform is to realize the free convertibility of RMB. From 65438 to 0996, RMB was convertible under the current account of international payments. However, the rapid growth of China's international trade and investment, the development of China's financial market, China's accession to the World Trade Organization and the strengthening of regional economic cooperation all objectively require RMB to be convertible under capital account as soon as possible. Among the 43 capital trading projects classified by the International Monetary Fund, only 6 projects in China are still under strict control, and the other 37 projects are convertible to varying degrees, among which 8 projects are basically unrestricted. Therefore, China has achieved partial convertibility of RMB capital.