The central parity rate of the yuan, China's currency Renminbi (RMB), to U.S. dollar stood at 6.7781 Wednesday, compared with 6.7790 for Tuesday, according to the data released by the China Foreign Exchange Trading System.

The yuan-dollar central parity rate was 6.7720 on Friday, the strongest since China announced to unpeg the yuan from the U.S. dollar in July 2005.

China's central bank announced on June 19 that it would further the reform of the formation mechanism of the yuan exchange rate to improve its flexibility.