Abstract: In 1979 an earthquake of magnitude 6 occurred in Liyang County, Jiangshu province. The epicenter was located in the junction of a NE trending active fault, the known Maoshan fault, with a NW trending active fault, the Fangshan-Tiger Mt. fault.In this paper the focal mechanism of the major shock and several aftershocks has been studied and the strike of seismic fracture has been also determined by means of null vector data. The research results indicate that the Liyang earthquake was caused by a right lateral strike-slip dislocation with some normal dip-slip component along the east branch of the Maoshan fault belt under the action of the NEE compression stress field.From the observation of aftershocks, it can be suggested that both the source volume of the b-value of this earthquake sequence is rather small. Using Wyss method and Gibowicz empirical formula, we approximately estimated the stress-drop and the seismic moment as well as the apparent stress of the Liyang earthquake. In the mean time, on the basis of the field geological observations we pointed out tentatively that the Liyang earthquake was generated probably by the locked NE Maoshan fault associted with the left lateral shifting of the NW Fangshan-Tiger Mt. active fault. And this seemed to be a reasonable explanation for the recurrence of two destructive earthquakes being occurred there within 5 years.The authors assume that the Liyang earthquake can be regarded to be a low stress-drop event under a high stress background, implying that the south part of the North China fault block has been stepping into a active stage of high stress.