Abstract: The precursory index system of groundwater level for short imminent earthquake prediction has been set up haesd mainly on the quantitative (or semi-quantitative or qualitative) relation between several premonitory phenomena parameters (that is precursory index) and three earthquake parameters that have been obtained by the summary of historical event examples. The precursory indexes for the judgment of earthquake magnitudes are as follows the spatial distribution, the spatial and temporal migration, the quantity, the shape, the duration and the amplitude of the precursors. The precursory indexes for the determination of earthquake occurrence time are as the beginning and turning (ending) time, the quantity, the shape, the spatial and temporal migration and the rate (or amplitude) of the precursors. The precursory indexes for determination of seismic epcenters are as the spatial distribution pattern, the quantity and the density, the pattern, the spatial and the temporal migration, the related region with earthquake and the control area by the wells, the rate (or amplitude) and the spatial distribution of the precursors after last strong event.