Globally, approximately 55％ of the population lives in towns and cities.By 2050, the world's urban population will increase by 6 billion with an urbanization rate of 70％ (https://population.un.org/wpp/).Therefore, efforts toward environmental sustainability have increasingly attached importance to achieving a win-win outcome by promoting economic development and improving urban environments [1].The rapid urbanization of China is contributing greatly to the world's development and global urbanization.In particular, China's urban development has achieved unprecedented progress over the past 70 years.The urbanization rate increased from 10.64％ in 1949 to 59.58％ in 2018, and population migration from rural areas to cities increased by 774 million (http://www.stats.gov.cn/), generating a massive urban expansion in recorded human history [2].Unfortunately, the rapid urbanization has caused a series of environmental issues, such as encroachment into cultivated land, air pollution, urban heat islands, and high energy consumption, which have attracted global attention [3-5].Therefore.sustainable development and environmental quality promotion are becoming pivotal topics for future urban development in China [6,7].The accurate delineation of national urban expansion across 70 years and knowledge of trajectories, patterns, and state policies associated with the expansion are the overarching content and scientific foundation to address the environmental sustainability issues.