The Daxing Line of the Beijing Subway is a planned light rail line that will connect Daxing District south of the city with the subway network. It will extend Line 4 south from its southern terminus at Majialou, on the 4th Ring Road in Fengtai District, to Nanzhao Lu, beyond the 6th Ring Road in Daxing District.
The Daxing Line will be approximately 22.2 km in length with 18 km underground. Of the 12 planned stations, only Xihongmen will be above the surface. Full-scale construction began in 2007 and the line is scheduled to open on December 28, 2010. The line will run six-car trains and will take 39 minutes to travel from Nanzhao Lu to Xidan.