Indeed, Guangshen railway is the first place in China to carry out successfully speed-up on the existing railroad. At the beginning of the 1990s, Guangzhou Railway Bureau and the Ministry of Railways carried out the pre-feasibility research about raising the maximum speed of passenger trains to . At 28 December 1991, the construction of the third line of Guangshen railway, and the speed-up improvement works of original double tracks started. In October 1994, the maximum speed of a train reached during the test. At 22 December 1994, the first sub-high speed () passenger train in China started commercial operation between Guangzhou and Shenzhen.
