Abstract: The water pollution condition in the Harbin reach of the Shonghua River is very serious.Surface water may infiltrate into the aquifer and influence the groundwater quality of the Harbin-City.The purpose of this paper is to investigate the pollution characteristics of surface water and groundwater,and their purification capacities.The results show that the purification capacities of both the river reach and the aquifer are potent and can be recovered naturally.Purification mainly includes dilution,adsorption,and filtration etc.Maintaining natural purification capacities are of great importance to protecting the grouudwater quality of the Harbin City.