Chengjiao line of the Zhengzhou Metro (Chinese: 郑州地铁城郊线; pinyin: Zhèngzhōu Dìtiě Chéngjiāo Xiàn), planned to be part of Line 9 in the future, is a rapid transit line in Zhengzhou.

It was opened on 12 January 2017.

This line is 40.84 km (25.38 mi) long with 19 stations (16 stations in operation).

[2] Through services are operated on Line 2 and Chengjiao line, although they are classified as separate lines.

[3]