The People's Bank of China said that Chinese banks made a net foreign-exchange purchase of 397.9 billion yuan ($65.5 billion) in November.
It was the second-largest tally this year, according to The Wall Street Journal. October saw a net inflow of 441.6 billion yuan.
Analysts believe the figures are speculative, betting on the strengthening of the yuan against the US dollar.
The Chinese yuan has appreciated around 2.6 percent against the greenback year-to-date.