National debt, also known as national debt, is a creditor-debtor relationship formed by the state raising funds from the society on the basis of its credit and according to the general principle of bonds. It is a debt certificate issued by the central government to investors, promising to pay interest and repay the principal within a certain period of time. Because the issuer of national debt is the country, it has the highest credit and is recognized as the safest investment tool.

China's national debt refers to the national debt issued by the Ministry of Finance on behalf of the central government. Guaranteed by the national financial reputation, the credibility is very high. It has always been called "Phnom Penh bond", and cautious investors like to invest in government bonds.

There are three kinds of bonds: voucher bonds, bearer bonds and book-entry bonds.

In the domestic market, the yield of ten-year government bonds is the basis of RMB asset pricing. Because the yield of 10-year treasury bonds is guaranteed by the national credit, long-term bonds are usually regarded as risk-free rate of return, and the asset prices in the stock market, futures market and real estate market all depend on the risk-free rate of return in the market (10-year treasury bonds yield).