China's unprecedentedly rapid urbanization has relied on large-scale construction activities enabled by huge amount of materials consumption such as steel and cement. In order to identify China's urban expansion patterns by revealing the relationships among urban land, buildings, and materials, this study collected and analyzed data of total urban built-up area, residential land area, dwelling area, and the amount of construction materials of 30 provinces during 1985-2010. The results show that the year 2000 is an important tipping point in China's urban expansion. Before 2000, total urban built-up area, dwelling area, and the amount of construction material stocks in China were all relatively small and the variances among 30 provinces were insignificant. While after 2000, both the amounts of these three parameters and the variances among the provinces increased rapidly. On regional scale, provinces in eastern China ranked the highest in total urban built-up area, dwelling area, and the amount of construction material stocks, followed by those in central and western China. At the same time, variances among provinces in eastern China were the largest in all three parameters, followed by those in western and central China. In most provinces, the total urban dwelling area and the amount of construction materials increased with the expansion of total urban built-up area. These findings indicate that most cities expanded horizontally in the early stage of urbanization. Because of the spatial reorganization and land-use replacement in the progress of urbanization, many single-floor and low-rise buildings were replaced by high-rise buildings in the cities. It indicates that instead of relying on horizontal expansion of the land, the urbanization in China after 2000 depends more on vertical expansion which consumes high-intensity and low-cost construction materials, leading to more dwelling area than total residential land area in many cities. Urbanization that relies on land "created" by construction materials can fulfill cities' demand for space as well as promote urban ecological space protection and sustainable development. However, the environmental impacts caused by the production, transportation, consumption, and disposal of construction materials are also concerning issues being worth of further research.