Abstract: In this paper, the changes of Liaohe Estuary coastline of a period of more than 30 years was studied by using 4 phases of Landsat data, which were 1979, 1990, 2000 and 2013. The result show that: (1)The coastline of Liaohe Estuary continuously moves forwards to the sea from 1979 to 2013. At present, the total length of the coastline is 298 km, which increased 63km comparing to 1979, while land area increased 410 km2. (2) Natural coastline of Liaohe Estuary reduced significantly with nearly 70% of the muddy coastline transforming into reclamation coastline of port, salt pan and farming. From 1979~1990, the muddy coastline transformed into reclamation coastline of salt pan and farming,however, salt pan coastline transformed into port coastline because of the construction of Panjin Port with the new century coming.(3)The coastline of the Liaohe Estuary has 3 change rates which are 94.2 m/a at the period of 1979~1990, 52.1 m/a at the period of 1979~1990 and 81.0 m/a at the period of 2000~2013. In the town of Erjiegou,the coastline moved forwards to the sea rapidly because of the construction of the salt pan, and the coastline change rate reached up to 1200 m/a in the period of 1990~2000. (4) Liaohe riverway changed greatly.Due to the large-scale aquaculture development and salt pan construction, Shuangtai River gate to the sea narrowed; Due tothe construction of salt pan and port, Big Liaohe gate to the sea also narrowed; Shuangtai riverway and Daliaohe riverway narrowed because of siltation and the reclamation. Mainly due to siltation and the reclamation, Shuangtaizi riverway and Daliaohe riverway narrowed partially.