Abstract: Evolution of tidal deposition system in Liaohe River has been studied using drilling and shallow substrata data since Holocene. Three sedimentary facies have been recognized,including tidal bank facies, abandoned tidal channel facies and shallow sea facies as well as facies of the old tidal delta under them. There was a small bay among the old Liaohe River, the old Dalinghe River and the Raoyanghe River from the beginning of Holocene to 1896. After the Shuangtaizi River became the floodway in 1896, Gaizhou bank formed and developed quickly. The amount of runoff was reducing, causing the tidal channel to be abandoned after the floodgate was built up in 1969.