Abstract: Based on RS and GIS, combined with multi-phase remote sensing image data, topographic maps and historical charts, this paper quantitatively analyses the feature of coastline changes in Liaoning Province during 100 years. It shows that since 1909, great changes of the formation and length of the coastline have taken place in Liaoning Province, with increasing of the land area. Throughout the whole province, in terms of the time change, the period from 1909 to 1932 saw the greatest change in the coastline and the largest increase in land area with fast annual increase rate. The period from 1950 to 1980 witnessed the minimum rate of shoreline change. In terms of space, shoreline change differs very uneven from place to place, with the main changes of muddy coast of Liaodong Bay in the northern area, least change of rocky section of the basement near Dalian, and the most significant change of Shuangtaizi River, Fuzhou Bay and Dayang River zone.