Abstract: Check systems play an important role in redistribution of water resources at small basin in Loess Plateau. A check dam system which was located at Liudaogou Basin on the northern Loess Plateau was chosen as the study area to analyze annual water budget of the check dam system. A hydraulic calculation model was developed based on actual geographic conditions. Validity of the model was verified by numerical simulation of the observed groundwater level. The numerical results in 2006 showed that surface runoff, evapotranspiration, downward infiltration and groundwater outflow accounted for 36%, 49.3%, 11.6% and 3.1% of the total water inlet, respectively. The results indicated that the effects of the check dam system on the water resources redistribution were mainly in reduction of surface runoff, increase of evapotranspiration and contribution to downward infiltration. Meanwhile, the proposed numerical method for research on hydrological cycle of the check dam system on the northern Loess Plateau is practical.