Abstract: The hiatus surface between Neogene and Eogene in the east depression of Liaohe basin was formed in the transition period from the rifting stage to post-rifting of the basin evolution. Beneath the surface，sediments formed in faulted depression were eroded due to tectonic uplift in the last stage of Eogene. Basing on calculated erosion amount of some wells in different tectonic positions and analyzing the relation between erosion and topography， the thickness of eroded sediments of N/E in the north region of this depression had been recovered The result indicated that，with regard to the whole region，the erosion amount in the north was larger than that in the south. It also suggested that the erosion amount was smaller in the area where paleo-river bed located than that in the river banks.