A solid understanding of urbanizing China – the world’s largest and most rapidly transforming urban society – calls for improved urban data provision and analysis. This paper therefore looks at major technological, social–cultural, and institutional challenges of understanding urban China with open data, and showcases our attempt at understanding Chinese cities with open urban data. Through our showcases, we hope to demonstrate the usefulness of open urban data in (1) mapping urbanization in China with a finer spatiotemporal scales; (2) reflecting social and environmental dimensions of urbanization; and (3) visualizing urban China at multiple scales.