Abstract: The Action Plan for Prevention and Control of Water Pollution demands that the basic ecological water demand of rivers and lakes should be maintained, especially the ecological base flow in dry season. To study river water resources of Liaohe River Basin during the dry season of 2018, sub-meter resolution satellite images were examined to obtain information for the location, length and ratio of dried up river beds. Spatial distribution, river grades, state control sections and drying-up reasons were characterized. Drying-up in the study area was found serious in dry season, with an increasing trend from east to west. Small and medium rivers were found to be more serious in drying-up. Some state control sections also dried in dry season. The dry-up in river beds was caused by climate factors and human activities. Management of water resources should be strengthened, monitoring and supervision should be carried out by means of satellite remote sensing and other advanced scientific and technological measures, so as to ensure the ecological base flow of rivers and maintain water ecosystem health.