Abstract: The frequent flow cutoff has serious effect on eco-environment of the region along the lower Yellow River. The authors studies the impact on lateral seepage quantity and groundwater cycling caused by flow cutoff of Yellow River and compares it with that of the year 1999 through the numerical simulation model of groundwater flow system of affected zone. The lateral seepage quantity will decrease 53.8% on condition that the flow cutoff stage from Huayuankou to river entrance and breaking time is 300 days. The lateral seepage quantity will decrease 46.3% if flow cutoff from Jiahetan to river entrance and breaking time were 300 days，and it will decrease 75.2% if flow cutoff occurs throughout the year. The lateral seepage quantity will decrease 19.8% if flow cutoff from Luokou to river entrance and brea king time were 300 days，and it will decrease 25.1% if flow cutoff throughout the year. The lateral see page quantity will decrease 4.7% if flow cutoff from Lijin to river entrance and flow cutoff throughout the year. Flow cutoff of Yellow River has minor effect on shape of groundwater flow domain of affected zone，so the boundary feather of shallow groundwater system will not change. Though flow cutoff has major influence on the riverside source fields in the lower Yellow River，yet it won’t has great effect on groundwater resources in the affected zone of Yellow River.

Key words: flow cutoff of Yellow River, lateral seepage quantity of Yellow River, groundwater cycling