Foreign direct investment (FDI) into the Chinese mainland increased 5.25 percent year on year in 2013 to reach 117.59 billion U.S. dollars, the Ministry of Commerce said Thursday. In December alone, the country's FDI inflow rose 3.3 percent from one year earlier to 12.08 billion U.S. dollars, the ministry's spokesman Shen Danyang said at a press conference.