Abstract: Part of the water from the SouthtoNorth Diversion Project may be stored in aquifer for groundwater conservation. To examine waterrock interactions and provide reference for water use, the experiment tests are conducted using the water from the Danjiangkou reservoir, the groundwater and the sand in the western suburb of Beijing to carry out seven aquifer simulations with the two water sources. The result shows that when the percentage of the Danjiangkou water is large, the cationexchange adsorption and the potassium feldspar dissolution may occur. Explicit nitrification occurs in each aquifer. The larger the percentage of the Danjiangkou water, the more obvious the nitrification. The carbonate balance may generate in each aquifer. Dolomite and calcite are dissolved in each simulation aquifer under the supersaturation state, indicating that injection using the Danjiangkou water will lead to the rise in groundwater hardness.