This polygon dataset represents city boundaries in China from 1991. The attribute table includes the GB codes and names in Chinese and English (Pinyin). All data is copyrighted by China Data Center and/or its suppliers. Derived works that include the source data must be merged with other value-added data in such a way that the derived work cannot be converted back to the original source data format. This data is licensed by UC Berkeley for research, educational, and other non-commercial use by authorized users, which include persons affiliated with UC Berkeley and walk-in users who must access the data in person at the library.The data sources for the layers in the collection "Administrative Boundary Maps of China, 1949-2014" include the following primary sources: “The Historical Changes of Administrative Regions of China, 1949-1983” (three volumes); 《中华人民共和国县级以上行政区沿革》（三册，1949-1983年）“The Atlas of Changes of Administrative Regions of China”;《中华人民共和国行政区划沿革地图集》The yearly publications of “The Administrative Regions”, 1985-2014; 每年的出版行政区划简册（1985-2014年）The web site for administrative regions: www.xzqh.org; 行政区划网www.xzqh.org