Photo taken on Nov. 15, 2010 shows the ceremony of the completion of track laying of Beijing-Shanghai high-speed railway in Bengbu City, east China's Anhui Province. The last track has been laid at Bengbu section of the Beijing-Shanghai high-speed railway on Monday morning, marking the completion of track laying of the entire 1,318-km railway. [Xinhua/Guo Chen]

The laying of tracks for the high-speed railway connecting Beijing and Shanghai, China's two most important cities, was completed Monday morning, in the latest milestone in the construction of the world's longest high-speed railway.

The 1,318-kilometer-long line will link Beijing, the Chinese capital in the north of the nation, and Shanghai, the country's eastern economic hub.

Construction on the 220.9 billion yuan (33.3 billion U.S. dollars) project started in April 2008. The line is scheduled to open in 2012.

Once completed, train travel time between the two cities will be slashed to about four hours from the current 10 hours.

The line will link China's two important economic zones - the Pan-Bohai Bay area in north China and the Yangtze River Delta region - by passing through some of China's richest and fast-developing provincial-level regions - Tianjin, Shandong and Jiangsu.

China launched its first high-speed line - a service linking the capital and the port city of Tianjin - at the time of the Beijing Olympics in 2008.

Since then, more fast-train lines have been put into service: the Wuhan-Guangzhou line linking central and south China; the Zhengzhou-Xi'an line connecting central and western China; and the Shanghai-Nanjing line in the country's east.

Last month, a 202-km high-speed line linking Shanghai and Hangzhou, capital of east China's Zhejiang Province, came into operation, extending the nation's in-service high-speed rail network to 7,431 kilometers.