There is a huge discrepancy between the calculated permeability coefficient and the actual situation of the aquifer being due to some factors such as the complexity of the hydrogeology and the diversity and relative difficulty of counting accurately. With specific illustration,this paper will take the experiment with the steady flow pumping test of the fully penetrating well in the coal-bearing strata aquifer in XJ-7,an exploration area,as an example. In this experiment,we took different methods of analyzing the statistics of groundwater level decrease and water-level recovery respectively. Through the comparison between these two methods,we find out that the result of the latter counting method that K = 0. 058 9 m·d^-1is much accurate and reasonable. This experiment thus demonstrates the permeability coefficient is of low accuracy when applying the Dupuit Formula into the practice of single-hole steady flow pumping test. By contrast,the counting result in the water-level recovery period is much more reliable because of the smaller and insignificant influence of both human and mechanical factors.