Zhengzhou - Wikipedia Zhengzhou,[b] previously romanized as Chengchow, [c] is the capital and the largest city of Henan Province, China With a population of 12 6 million people in 2021, it is China's 11th largest city by population [7] Zhengzhou is situated in north-central Henan Province at the eastern foothills of the Xiong'er Mountains and on the southern bank of the Yellow River; [8] where its valley widens