Abstract: According to stress field of the focal area, six types of earthquakes may be recognized, i. e. tension, compression, contortion and their transitional types. In the Xinfen-gjiang reservoir the main shock and most aftershocks of Ms>3 belong to the contortion type and are the same as most tectonic shocks outside the reservoir area. But in the last decade or so, the most microseisms belong to the tension type. The aftershocks have a more complicated driving mechanism than the main shock.In present, the seismic magnitude in Xinfengjiang areas correlates with the energy release of continental China but with a time lag. It has been a general view that a strong earthquake sequence in the neighboring regions may cause considerable events in the induced seismic reservoir.