It is an importantpart of coastal restoration to identify the characteristics of natural coast. However, it is difficult to know the natural coast characteristics of uninhabited islands discarded after their development due to the lack of historical references. The study on the Qiandalian Island located in the central part of the Pulandian Bay of Dalian City has demonstrated that the location and property of natural coast of the uninhabited islands can be analyzed and identified based on the historical remote sensing images and the geological and geomorphic status of the existing coast. From the KH satellite images obtained in 1972, it can be recognized that the coast of the Qiandalian Island remained its natural shape at that time. However, its position is now within the island land behind the coast of 2020. Combined with the coastal geological survey carried out in 2020, it can be further identified that at the time of 1972 bedrock coast in the form of sea cliffs was distributed in the eastern and western parts of the Qiandalian Island and a gravel coast in the southern and northern parts. From 1972 to 2020, all the natural coast of the Qiandalian Island changed into artificial one and also the length of the coast increased from 2.38 km to 3.12 km.