As of December 31, 2021, a total of 9192.62 km of urban rail transit lines have been put into operation in 50 cities in mainland China, of which metro lines are 7253.73 km, accounting for 78.9 %. Additional 5 cities including Luoyang, Jiaxing, Shaoxing, Wenshanzhou, and Wuhu have operated the urban rail transit in 2021, of which Luoyang and Shaoxing are urban subway operation cities, while Wuhu operated the straddle-type monorail. In addition, 30 cities including Beijing, Shanghai, Tianjin, Chongqing, Guangzhou, Shenzhen, Wuhan, Nanjing, Shenyang, Changchun, Dalian, Xi'an, Harbin, Suzhou, Zhengzhou, Hangzhou, Foshan, Ningbo, Wuxi, Nanchang, Qingdao, Nanning, Hefei, Shijiazhuang, Guiyang, Xiamen, Jinan, Changzhou, Xuzhou, and Zhuzhou have also opened new lines or sections.

A total of 1222.92 km of new urban rail transit lines in operation were added in 2021. There are 39 new operation lines and 23 newly opened extension sections and the second-phase sections of existing lines. A total of 8 systems make up the newly added1222.92 km of urban rail transit lines, of which 971.93 km are metro lines, accounting for 79.48 %; urban rail is 133.15 km, and the straddle-type monorail is 46.31 km; 38.73 km are trams, 15.54 km is the drifter roller rail system, and 14.0 km is the autonomous roller rail system; light rail is 2.2 km, and the electromagnetic levitated traffic lines are 1.2 km.