The history of the city of Yingkou is deeply rooted in the distant past, as the first settlements in this territory date back to the Paleolithic era. However, it began to take shape as a significant settlement much later. In 1688, the Qing government resettled Bargu Mongols here, founding a settlement called "Yingzi," which means "military camp." Over time, due to the characteristics of the local tides, it came to be known as "Yingkou" — "The Estuary at the Military Camp." The city gained widespread fame in the 19th century when Europeans mistakenly referred to it as Newchwang, after another settlement located further up the river.
A key moment in the history of Yingkou was its transformation into an international trading port, facilitated by several factors. Firstly, its advantageous geographical location in Liaoning Province, at the mouth of the Liao River where it flows into the Bohai Sea, made it the natural maritime gateway for all of Southern Manchuria. Secondly, the impetus for development was the Treaty of Tientsin in 1858, which opened the port of Newchwang to foreign trade. Since the river at that location was too shallow for sea-going vessels, the port was effectively moved to the coast, to the site of modern Yingkou, where a customs house began operations in 1866.
With its opening to international trade, Yingkou quickly turned into a bustling economic and cultural hub and remained the main port of Manchuria until the early 20th century. The city's growing political importance in the late 19th and early 20th centuries attracted the attention of foreign powers, whose presence intensified after the First Sino-Japanese War of 1894-1895 and during the "Boxer Rebellion." A European quarter formed in the city, inhabited by foreigners primarily engaged in trade — by 1891, there were already about 140 of them, half of whom were British. The city's economy was based on port activities, ensuring the export and import of goods for the entire northeast of China. In addition to trade, fishing, salt production, and various industries developed actively.