The 643-km-long railway line for passenger transport links Xi'an, capital of northwest Shaanxi Province to Chengdu, capital of the southwestern province of Sichuan. It is the second major line after 1300 km long Beijing-Shanghai line which was launched last year.
The new project will be completed in five years with an investment of more than 40 billion yuan (about USD 6.35 billion).
The travel time between the two cities will be shortened to three hours from 12 hours currently, after the new railway is put into operation.
The line will have 127 km of tunnels to pass through the Qinling Mountains.
China aims to basically complete the construction of a high-speed railway network with a total operating length of more than 40,000 km by the end of 2015, official media reported.