Abstract: The monitoring wells penetrating fault zones can provide special information on tectonic activity. The groundwater regime in the fault zones is an integrated interaction result of various factors such as geological structure activities and rainfall, etc. Simulating the groundwater level change caused by rainfall is beneficial to accurately identifying the anomalies induced by tectonic activities. Based on the characteristics of groundwater circulation in the fault zones, a tank model combing rainfallgroundwater regime has been established. In this model, response function method is employed to express the retard of infiltration recharge. The model is used to simulate the groundwater regime of a monitoring well in the Babaoshan fault zone during 2007mdash;2008. Four anomalous rises of groundwater level were identified during the period. Those anomalies may be related to the intermittently creep of Babaoshan fault zone.