Daliao River in the context of "Catchment"

The Liaodong or Liaotung Peninsula (simplified Chinese: 辽东半岛; traditional Chinese: 遼東半島; pinyin: Liáodōng Bàndǎo) is a peninsula in southern Liaoning province in Northeast China, and makes up the southwestern coastal half of the Liaodong region. It is located between the mouths of the Daliao River (the historical lower section of the Liao River) in the west and the Yalu River in the east, and encompasses the territories of the whole sub-provincial city of Dalian and parts of prefectural cities of Yingkou, Anshan and Dandong.

The word "Liaodong" literally means "Liao region's east", referring initially to the Warring States period Yan commandery of Liaodong, which encompassed an area from modern Liaoning-Jilin border in the north to the Chongchon River on the Korean Peninsula in the south, and from just east of the Qian Mountains to a now-disappeared large wetland between the western banks of middle Liao River and the base of Yiwulü Mountain, historically known as the "Liao Mire" (遼澤, Liáo zé) roughly in between the modern Xinmin, Liaozhong, Tai'an, Panshan and Beizhen). The modern usage of "Liaodong", however, simply refers to the half of Liaoning province to the left/east bank of the Liao/Daliao River.

Yingkou (Chinese: 营口; pinyin: Yíngkǒu) is a coastal prefecture-level city of central southern Liaoning province, People's Republic of China, on the northeastern shore of Liaodong Bay. It is the third-smallest prefecture level city in Liaoning with a total area of 5,502 square kilometres (2,124 sq mi), and the ninth most populous with a population of 2,328,582 as of the 2020 census, of whom 1,228,198 lived in the built-up (or metro) area made of three urban districts (Zhanqian, Xishi and Laobian) and one county-level city (Dashiqiao). It borders the sub-provincial city of Dalian to the south, the prefectural cities of Anshan to the north and east and Panjin to the northwest, and also shares maritime boundaries with Jinzhou and Huludao across the Liaodong Bay to its west.

Located on the east bank of the Daliao River mouth, Yingkou is an important port city, with the Port of Yingkou being the second-largest container port in the Bohai Sea (after the Port of Tianjin) and Northeast China (after the Port of Dalian), the tenth-largest nationwide, and the 25th-busiest worldwide. Yingkou is classified as a Medium-Port Metropolis.