The value of bonds issued in China totaled 2.9 trillion yuan (about 426 billion U.S. dollars) last month, down by about 100 billion yuan from April, the central bank said Tuesday.
Bonds issued on the inter-bank market reached 2.7 trillion yuan, data from the People's Bank of China (PBOC) showed.
The balance of outstanding bonds was 67.1 trillion yuan by the end of May, up from 66.9 trillion yuan at the end of April and 63.7 trillion yuan at the end of last year.
China supports development of direct financing to reduce costs of enterprises, allowing them to get funds by issuing shares or bonds, rather than from commercial banks.
PBOC said in February that the country will give full play to the bond market's role in raising the share of direct financing, containing financial risks and optimizing resource allocation.
In 2016, China issued 36.1 trillion yuan in various kinds of bonds, up 54.2 percent from 2015, data showed.