Abstract: The restoration of water ecological integrity in Liaohe River Basin is typical and representative for the basins with developed heavy chemical industry and water shortage in cold regions. The problems of water ecological integrity in Liaohe River Basin of Liaoning Province were analyzed from the aspects of water resources development and utilization structure, pollutant discharge, water environment capacity and changes of aquatic biodiversity. The technological research and development achievements of National Major Science and Technology Program for Water Pollution Control and Treatment (referred to as the “Water Program”) in Liaohe River Basin of Liaoning Province during the 11th and 12th Five-Year Plan periods were summarized. On this basis, the practice of water ecological base flow guarantee for physical integrity, the practice of pollution reduction for chemical integrity in the whole process of heavy pollution industry, and the practice of water ecological restoration for biological integrity were expounded. Some suggestions were put forward from the aspects of the characteristics of large river basins, the necessity and important content of water ecological integrity restoration, the way to coordinate water resources, water environment and water ecology in the treatment, and the way to carry through the three integrity restoration thoughts of physics, chemistry and biology, so as to provide experience and reference for the prevention and control of water pollution in large river basins.