China's high-speed railway line linking Beijing and Shanghai has recorded over 100 million passenger trips since it started operation in June 2012, railway authorities announced on Thursday.

Built with an investment of 217.6 billion yuan ($34.7 billion), the 1,318-km railway linking Beijing and Shanghai has shortened the travel time between the two major cities to about five hours from the previous eight hours or more.

China has been steadily expanding its rail network as trains are the most commonly used vehicles for the country's long-distance travellers.

In December last year, the high-speed line linking Beijing and Guangzhou -- the world's longest -- went into official service, bringing China's total high-speed rail network in operation to a length of more than 9,300 km.

The Beijing-Guangzhou line is one of four north-south lines expected to serve as backbones for the country's high-speed railway network, which also features four east-west lines.

China's rail construction boom took a hit in 2011 following a deadly train collision near the eastern city of Wenzhou, the accident resulting in 40 deaths and 172 people being injured.

Investment and construction gradually picked up last year as the country set the aim of having around 120,000 km of railway lines in operation by 2015, including 18,000 km of high-speed lines.