Acer ningmingensis Y.F.Chen & W.O.Wong sp.nov. is described for asymmetric samaras from the Oligocene Ningming Formation in Guangxi Zhuang Autonomous Region, South China. It represents the Oligocene Acer occurrence in the lowest latitude and the only record from a tropical zone today. Together with the coeval fossil record from the mid-latitudes in China, Korea and Japan, the present discovery suggests that the genus Acer had been widely distributed in East Asia by the Oligocene, during which the climate in the Ningming area was cooler than the present.