The central bank on Thursday injected more money into the market for the fourth day in a row this week.
The People's Bank of China (PBOC) put 60 billion yuan (9.14 billion U.S. dollars) into seven-day reverse repos, a process by which central banks purchase securities from banks with an agreement to sell them back in the future.
The reverse repos were priced to yield 2.25 percent, unchanged from the previous operation, according to a PBOC statement.
Reverse repos worth 30 billion yuan matured on Thursday, so the central bank has effectively pumped 30 billion yuan into the market.
This week, liquidity is relatively tight as companies pay taxes and commercial banks face the central bank's macro-prudential assessment as the second quarter draws to a close.
On Thursday's interbank market, the benchmark overnight Shanghai Interbank Offered Rate, known as Shibor, rose 0.5 basis point to 2.032 percent.
