Determining hydrogeological parameters is one of the important tasks of groundwater dynamics, in which the storage coefficient is an indispensable parameter to predict subsidence. Compaction and water-level data were assumed to collect data from a borehole extensometer recorded and groundwater pumping test in My Thuan bridge, Vinh Long province to estimate elastic and inelastic specific coefficient (S) in aquifer-system. The purpose of this study is to estimated and compared specific storage by three methods such as Theis’s method, Riley’s method and Galloway’s study in My Thuan bridge site, Vinh Long province. The final value of the storage coefficient is 0.00052. The results of this study also are the basis for calculating settlement and the impact that mining may have on regional groundwater flow systems.