Urbanization’s rapid progress has led to many big cities, which have modernized people’s lives but also engendered big challenges, such as air pollution, increased energy consumption and traffic congestion. Tackling these challenges can seem nearly impossible years ago given the complex and dynamic settings of cities. Nowadays, sensing technologies and large-scale computing infrastructures have produced a variety of big data in urban spaces, e.g. human mobility, air quality, traffic patterns, and geographical data. The big data implies rich knowledge about a city and can help tackle these challenges when used correctly. This workshop provides the professionals, researchers, and practitioners who are interested in sensing/mining/understanding urban data with a platform where they can discuss and share the state-of-the-art of urban computing development and applications, present their ideas and contributions, and set future directions in emerging innovative research for urban computing.