Phreatic water resources are widely found in thick unconsolidated surface layers in western China, where water levels respond sensitively and quickly to large-scale underground mining in conjunction with shallow coal seams. Longwall face #32201 of the Bulianta Coal Mine, in the Shendong coalfield was selected as an industrial trail base, where field observations on ground-water levels were conducted when the working face was below a water-rich area. The space-time variation in the behavior of un-consolidated water levels in response to underground mining and its relation with of advance were observed through the field trials. The basic conditions for water preservation in mines are presented and the mechanisms of water preservation in mining analyzed, given the geological condition of two key strata and a severely weathered layer buried in the overburden. The field trails show that water preservation in mining shallow coal seams can be successful under suitable conditions, providing new technology for envi-ronmental protection in the desert coalfields of northwestern China. Phreatic water resources are widely found in thick unconsolidated surface layers in western China, where water levels respond sensitively and quickly to large-scale underground mining in conjunction with shallow coal seams. Longwall face # 32201 of the Bulianta Coal Mine, in the Shendong coalfield was selected as an industrial trail base, where field observations on ground-water levels were conducted when the working face was below a water-rich area. The space-time variation in the behavior of un-consolidated water levels in response to underground mining and its the basic conditions for water preservation in mines are presented and the mechanisms of water preservation in mining analyzed, given the geological condition of two key strata and a severely weathered layer buried in the overburden. field trails show that water preservation in mining shallow coal seams can be successful under suitable conditions, providing ne w technology for envi-ronmental protection in the desert coalfields of northwestern China.