Abstract: Excessive exploitation for groundwater can cause serious land subsidence and land fissures in the southern Yangtze River Delta, resulting in huge economic losses. The occurrence and development of land subsidence and land fissures are closely related to the exploitation of groundwater in time and space, with the rate of land subsidence increasing obviously at the peak of groundwater exploitation and reducing significantly and even rebounding slightly during the stable or recovery periods of groundwater. Horizontally, the distribution pattern of land subsidence has strong correlation with that of groundwater level in the main mining layers; vertically, to the thickness of the main mining layers, soil layers and compression property. Both aquitard and aquifer can be main subsidence layers. The deformation of soil layers, triggered by exploitation for underground water, is closely related to the change process of groundwater level; plastic and visco plastic deformation occurs not only in aquitard but in water-bearing sand layers even under the condition of certain water level change. Land subsidence is accumulative effect of deformation of various subsurface layers. In order to control the development of land subsidence and land fissures, it is suggested in this study that exploitation amount of groundwater should be restricted, especially avoid the water level from reaching the lowest level occurring in the history of the soil layers.