Abstract: Based on statistics and comparison of surveyed data, with plotting of correlative curves, the Songnen Plain is studied on both natural and artificial factors that impact the groundwater table. The natural factors include climate, hydrology, topography, geology, hydrogeology, biology and soil. The artificial factors involve mining and recharge of groundwater. It is concluded that, beside the decrease of rainfall, the most important reasons for the reduction of groundwater resources in Songnen Plain are the water control projects and groundwater mining by human beings. That is the key factor to impact the dynamic change of groundwater table.