The Port Arthur massacre (Chinese: ) took place during the First Sino-Japanese War from 21 November 1894 for three days, when advance elements of the First Division of the Japanese Second Army under the command of General Yamaji Motoharu (18411897) killed somewhere between 2,600 civilians and 20,000 including Chinese soldiers in the Chinese coastal city of Port Arthur (now Lshunkou District of Dalian, Liaoning).Reports of a massacre were first published by Canadian journalist James Creelman of the New York World, whose account was widely circulated within the United States. In 1894, the State Department ordered its ambassador to Japan, Edwin Dun, to conduct an independent investigation of Creelman's reports.

Lüshunkou District (also Lyushunkou District; simplified Chinese: 旅顺口区; traditional Chinese: 旅順口區; pinyin: Lǚshùnkǒu Qū) is a district of Dalian, Liaoning province, China. Also formerly called Lüshun City (旅顺市; 旅順市; Lǚshùn Shì) or literally Lüshun Port (旅顺港; 旅順港; Lǚshùn Gǎng), it was formerly known as both Port Arthur (Russian: Порт-Артур, romanized: Port-Artur) and Ryojun (Japanese: 旅順). The district's area is 512.15 square kilometres (197.74 sq mi) and its permanent population as of 2010 is 324,773.Lüshunkou is located at the extreme southern tip of the Liaodong Peninsula. It has an excellent natural harbor, the possession and control of which became a casus belli of the Russo-Japanese War (1904–05). Japanese and then Russian administration was established in 1895 and continued until 1905 when control was ceded to Japan. During that period, it was world-famous and was more significant than the other port on the peninsula, Dalian proper.