Traditional analysis for step- drawdown tests always uses selected data during the pumping period. In this paper,a new approach which was based on the Theis formula and the principle of superposition and all the data obtained from the tests were used to determine the aquifer parameters. The transmissivity and storativity could be obtained in confined aquifers and specific yield and hydraulic conductivity could be obtained from the unconfined aquifers. In addition,the coefficient of well lose and the exponen...