Eastern China. The area in yellow is administered by the People's Republic of China. The area in green covers Taiwan and other islands, claimed by the PRC and administered by the Republic of China. (The base map shows the area under effective control of the PRC and the ROC combined.)
The PRC lays claim over the Taiwan Province and parts of Fujian (also spelt Fukien or Fuchien), which are also defined as part of eastern China by the PRC. However, they are administered by the Republic of China.