Abstract: The groundwater flow system in the Chahantaohai ecological environmental improvement area, Inner Mongolia is composed of Upper Pleistocene alluvium pore water flow subsystem (Q₃^al), Middle Pleistocene alluvium pore water flow subsystem (Q₂^al), basement pore water flow subsystem, Holocene eolian sand pore water flow subsystem (Q₄^eol) and Holocene alluvium pore water flow subsystem (Q₄^al). Among them, the major mining bed is Q₃^al. All the other subsystems are the recharge beds for Q₃^al. The Q₃^al, Q₄^eol and basement groundwater flow subsystems receive the influent seepage recharge from the meteoric water, and then discharge at the eastern edge of Q₃^al. In natural condition, the Q₃^al subsystem receives recharge from Yellow River during flood peak and overflow stages, while discharges to Yellow River in other seasons.