Abstract: The data on coastline types and their dynamic changes are critically important for the rational development, ecological protection, and restoration of coastal zones. Based on historical maps, remote sensing images and field survey verification, this study acquired coastline data of Liaoning Province across for six periods (1894, 1940, 1975, 2000, 2010 and 2020). By integrating historical literature, we further examined the spatiotemporal evolution characteristics and driving mechanisms of coastline changes in the region. The results show that: ①Over the past 120 years, the measured lengths of the six historical shorelines in Liaoning Province were 1673.5 km, 2137.34 km, 2052.57 km, 2045.27 km, 2047.54 km and 2516.49 km, respectively. During this period, the proportion of natural coastline declined sharply, a trend primarily driven by extensive land reclamation activities. ②From 1894 to 2020, 68.97% of the coastline advanced seaward at an average rate of 39.44 m/a (LRR), while 31.03% retreated landward at an average rate of 10.02 m/a (LRR). Specifically, from 1894 to 1940, erosion dominated the Daliaohe River estuary, whereas accretion occurred near the Liaohe River estuary; Between 1940 and 1975, the eastern part of the Liaohe estuary experienced erosion, while the western part showed accretion; since 1975, continuous sea enclosure and land reclamation activities have resulted in rapid coastline progradation, with the most significant changes observed along the Jinzhou section from 2010 to 2020. ③ Based on long-term data on sea enclosure and land reclamation from 1940 to 2020, the tidal flat area in Liaoning Province experienced a cumulative loss of 1,801.71 km², with the most significant reductions occurring in Jinzhou, Panjin and Dandong. ④ Analysis of the drivers on coastline changes indicates that from 1894 to 1940, changes were predominantly influenced by natural factors, including sea-level variations and sediment deposition, evidenced by the seaward progradation of the Liaohe estuary and the erosion retreat of the Dalinghe River estuary. During the period 1940-1975, changes were jointly controlled by natural and human factors, with typical erosion in the eastern Liao River estuary and accretion in the western section. From 1975 to 2020, human activities, particularly sea enclosure and land reclamation, became the dominant driver of coastal transformation. This study offers a scientific basis for the management of shoreline resources in Liaoning Province and other coastal regions.