Construction of a rail line linking Beijing's city center with its southern suburbs began on Sunday.
The 21.8-km line runs from the southern section of the city's Fourth Ring Road to the center of suburban Daxing District, known as an agricultural base for the capital.
The main work on the line was scheduled for completion in November 2009, and the line would be officially opened a year later, said Liu Jun, a project manager with the Beijing Rail Construction Management Company.
Eleven stations were planned on the line running through Fengtai and Daxing districts.
Zhou Zhengyu, deputy head of the municipal committee of communications, said in October that planned rail lines would raise the city's total rail length to 561 km by 2015, when rail transport would take half of the public traffic, and new towns in seven suburban districts would each have a rail line connected to the city center.
Beijing has eight subway lines with a total length of 200 km in operation. They are Lines 1, 2, 5, 10, 13, the Batong Line (an extension of Line 1), the airport express and a branch that links the Olympic Green with Line 10.