In this paper, using earthquakes occurring in a range of 20 km around Xiaolangdi reservoir from 2009 to 201, which were recorded after the digital transformation of Xiaolangdi seismic network at the end of 2009, we analyzed their spatial and temporal distributions and the focal mechanism solutions of 61 earthquake s among them. The results show that there are induced earthquakes in the Xiaolangdi reservoir in which weak shocks and micro earthquakes of largest M_L=2.8 predominate. The earthquakes are concentrated in two cluster regions, which are related to Shijinghe-fault and Tadi-fault respectively. The tensile stress axis of reservoir-induced earthquakes is basically consistent with that of maximum principal stress of tectonic setting; the dip angle is no longer horizontal, but about 30°. It shows that these earthquakes occur under the action of certain relatively vertical stress, which may be related to the long-term effect of reservoir water after the storage.