随着人口增长和经济持续发展，快速精准地获取城市建成区扩张信息，并对其时空特征进行深入分析，对于实现可持续发展具有重要意义。以2013年、2016年、2019、2022年4个时期的NPP/VIIRS夜间灯光数据为数据源，基于参考比较法提取城市建成区，分析陕西省城市扩张时空特征。结果表明：(1)2013—2022年陕西省建成区面积持续增长，增长速度整体呈现“先上升后缓慢下降”的趋势，各城市建成区不断向外扩展和延伸，呈现出不规则的扩展趋势。(2)在紧凑度和分形维数上，表现为城市以外部扩张为主，紧凑度水平整体较低，呈逐年降低的趋势，分形维数均值变化较小，研究区城市空间形态的形状比较规则，轮廓较为简单。(3)建成区标准差椭圆面积呈空间扩张趋势，中心移动速度逐渐减小，建成区扩张方向也出现一定的变化，在南北方向上有扩张态势，东西方向呈现出一定程度的收缩迹象，反映出陕西省南北经济发展不平衡。研究结果有助于更好地认识和理解陕西省城市化发展进程以及城市时空演变特征，为陕西省城市的健康、协调发展提供理论支撑。

With the growth of population and the continuous development of the economy, obtaining information on the expansion of urban built-up areas quickly and accurately and conducting in-depth analysis of their spatio-temporal characteristics are of great significance for achieving sustainable development. Taking NPP/VIIRS nighttime light data in 2013, 2016, 2019, and 2022 as the data sources, we used the reference comparison method to extract urban built-up areas, and analyzed the spatio-temporal characteristics of urban expansion in Shaanxi Province. The findings indicated that(1)the built-up area of Shaanxi Province consistently expanded from 2013 to 2022, with an overall trend of “increasing initially followed by a gradual decline”. Urban built-up areas continuously expanded outwardly, exhibiting irregular patterns of growth.(2) In terms of compactness and fractal dimension, the city primarily experienced external expansion, with a generally low level of compactness that was decreasing over time. The average fractal dimension showed minimal change, indicating that the urban spatial form in the study area has a regular shape and a simple outline for the urban built-up areas.(3)The standard deviation ellipse area of built-up area demonstrated a trend of spatial expansion, with a gradual reduction in center movement speed. There were also shifts in expansion direction. Specifically, there has been an expansion towards the north-south axis and a noticeable contraction along the east-west axis, reflecting the uneven economic development between the north and south of Shaanxi Province. The research results are conducive to a better understanding of the urbanization development process and the spatio-temporal evolution characteristics of cities in Shaanxi Province, providing theoretical support for the healthy and coordinated development of cities in Shaanxi Province.