Chengdu–Chongqing railway or Chengyu railway (simplified Chinese: 成渝铁路; traditional Chinese: 成渝鐵路; pinyin: chéngyú tiělù), is a single-track electrified railroad in the Sichuan Basin of Southwest China between the cities Chengdu and Chongqing. Chongqing's short form name is Yu (渝) and the railway is named after the two cities. The line has a total length of 505 km (314 mi).
The Chengyu railway opened in 1952 and was the first railway to be built after the founding of the People's Republic of China. Other cities along the route include Jianyang, Ziyang, Zizhong, Neijiang, Longchang and Yongchuan.
In 1903, a railway line between Chengdu and Chongqing, the two biggest cities in Sichuan, was proposed by Huguang Viceroy Zhang Zhidong as part of a railway from Sichuan to Wuhan. Construction on this line began in 1909 and halted in 1911. Attempts to resume construction in 1936 and 1947 ended with the outbreak of the Sino-Japanese War and the Chinese Civil War. On December 31, 1949, shortly after the Chinese Communists captured Sichuan from the Nationalists, Secretary of the Southwest Bureau Deng Xiaoping proposed the building of the railway. Work began on June 15, 1950 and involved 30,000 People's Liberation Army troops and 10,000 civilian laborers. More than 400 private steel mills in Chongqing supplied steel for the line. The line was completed on June 13, 1952, and entered into trial operation on July 1. It was the first railway line built in China after the establishment of the People's Republic of China.
In 1987, the Chengyu Line was fully electrified, raising annual carrying capacity from 6.1 million tons to 13 million. By 2008, the line was transporting 90 million tons of cargo and 70 million passengers per year.
After the opening of the Dazhou–Chengdu railway (达成铁路) (via Suining) in 1997, and the Suining–Chongqing Railway in 2006, another, shorter, railway route between Chengdu and Chongqing, via Suining (so-called 成遂渝铁路), 312 kilometres (194 miles) long, appeared. Since 2009, high-speed CRH passenger trains run on that route.
The third railway line between the two cities, the Chengdu-Chongqing high-speed railway, is now under construction, and will accommodate high-speed trains traveling at up to 350 kilometres per hour (217 miles per hour). Although it will follow a route generally similar to that of the original Chengdu–Chongqing railway, it will be significantly shorter due to the greater use of elevated sections and tunnels.