Official reserve assets are held by a country's monetary authorities, generally including gold reserves, foreign exchange reserves, reserve positions in the International Monetary Fund and special drawing rights. The official reserve project is an adjustment project or a balance project, which is mainly used to explain how the surplus and deficit of the balance of payments are adjusted to maintain the balance of payments. When there is a surplus in the balance of payments, the official reserve assets increase; On the other hand, if there is a deficit in the balance of payments, it must be made up by official reserve assets, so the official reserve assets are reduced. That is to say, when a country's balance of payments has a surplus and a deficit, it must achieve balance by increasing or decreasing official reserve assets.

When there is a surplus in the balance of payments, the official reserve assets increase.

Domestic fiscal surplus will not reduce official reserves, and there is no necessary connection between them. Official reserves are generally used for balance of payments.