||Recently, with the fast speed of urban expansion, research concerning the regulation of urban built-up area expansion is a significant topic, especially in Eastern China with its high urbanization level. The Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) nighttime light data has a high association with the urban-rural distribution, which provides a new method to study urban expansion effectively and with relatively high accuracy. Between 1998 and 2013, China experienced a rapid economic development period, making it crucial to learn the patterns and driving forces to better manage urban master planning and sustainable development. The urban built-up area for the research years are mapped, and the annual urban expansion speed, urbanization intensity index, and built-up area gravity center are analyzed in this paper. The results will show that the amount of the urban built-up area grows continuously from 1998 to 2008, with the development focus in southern Jiangsu, while from 2008 to 2013, the development center moves to northern Jiangsu. The main driving forces behind this urban built-up area expansion are population growth and economic development.