The benchmark weighted-average seven-day bond repurchase rate fell 7.72 basis points to 3.1271 percent from Tuesday's close of 3.2042 percent.

The 14-day repo rate inched down to 3.3275 percent from 3.4095 percent, but the shortest overnight one-day repo rate edged up to 2.5793 percent from 2.5363 percent.

China's central bank injected 277 billion yuan ($44.35 billion) into the banking system via open market operations on Tuesday and is expected to make another large injection on Thursday.

Maturing reverse repos and bills will cause a net drain of 523 billion this week, which will be offset by injections made during the regular open market operations on Tuesday and Thursday.

The central bank's new liquidity management strategy has evolved significantly this year as regulators rely increasingly on massive, but short-term, injections to micromanage liquidity on a weekly basis, instead of using blunter long-term tools that can cause macroeconomic distortions.

Dealers said they expect the central bank to generally keep liquidity loose for most of November and December, during which time the Ministry of Finance customarily injects 1 to 2 trillion yuan into the banking system to facilitate the partial refund of corporate income taxes pre-paid earlier in the year.

The interest rate swaps (IRS) were flat on Wednesday, with one-year IRS flat at 3.14 percent, unchanged from Tuesday's close, while the benchmark five-year IRS inched to 3.39 percent from 3.36 percent.