The reason why the denomination of Vietnamese dong is so large is inflation. In the past, Vietnam used copper coins as its main currency. When Viet Nam was a French colony, the currency was the French Indian zhina dollar. Vietnamese people call it a shield. After Vietnam's independence and reunification, the name Dun was still used. 1997 financial crisis, Southeast Asian currencies depreciated, and then faced high inflation. For example, in 2003, the inflation rate in Vietnam was as high as 25%. At the end of 2003, Vietnam issued two kinds of plastic banknotes with a face value of 500,000 rupiah and 50,000 rupiah respectively.