Abstract: We find that the average declining quantity of groundwater level is 0.7 meter per year through analyzing change process of the groundwater level in Taihang Piedmont. The season-changing quantity and the season-resuming quantity changed little in 1980's and increased very quickly in 1990's. Relationship between the precipitation and the declining quantity of the groundwater is highly linear correlation and the correlation coefficient is 0.7798. When yearly precipitation increases 100 millimeters, the groundwater level will ascend 0.66 meter. Only if water-saving agricultural system is constructed, and only if integrative management of forestry ecology is reinforced, then the situation that groundwater level is declined gradually can be controlled.