The value of bonds issued in China in May totaled 3 trillion yuan (456.35 billion U.S. dollars), nearly double the figure for the same period last year, the central bank said Thursday.

The total balance of the bond market was 54.7 trillion yuan by the end of May, according to the People's Bank of China (PBOC).

Commercial banks, non-bank financial institutions and other investors accounted for 58.03 percent, 9.05 percent and 32.92 percent of the total figure, respectively.

The central bank said in April that China will not limit investment by foreign central banks and similar institutions in the Chinese inter-bank foreign exchange and bond markets as long as they register their investments.

The surge in bond issuance suggests it is becoming easier for Chinese firms to find affordable financing. Financing costs for companies through bond issuance has significantly reduced since 2014, according to the PBOC.

However, the bond issuance value in May was slightly down from April's sum of 3.3 trillion yuan. Endi