It is vital for sustainable development of groundwater resource to understand the groundwater renewal rate in the piedmont of the Taihang Mountains. The purpose of this study is to estimate the groundwater renewal rate in an unconfined aquifer in the Shijiazhuang area based on tritium content and to discuss the changes of renewal rate along the flow path further. The results suggested that the mean annual renewal rates decrease with the depth of water table and the distance from the Hutuo River increasing. The mean annual renewal rates range from 5% a-1 to 33% a-1 of the aquifer volume in the upper part of alluvial fan and decrease to 3%—12% a-1 down- gradient to Shijiazhuang city. In the water depression area of Shijiazhuang

the mean annual renewal rates are 1% a-1 to 5% a-1 of the aquifer volume. If the median value is adopted as the representative of overall renewal rate of the area

the estimated recharge rate is about 242mm/a.