Moderate-strong earthquakes happened very frequently in the Liaodong peninsula. In addition to the Haicheng M7.3 earthquake in 1975,there are also 19 earthquakes of M≥5 recorded in this area. The earthquakes are distributed regularly,mainly restricted to seismic belts or to the grid nodes. The spatial distribution is accordant to the NE-NNE trending faults such as the Jinzhou Fault,the Yalujiang Fault,and to the NW-trending conjugated ones. Moderate-strong earthquakes happened mostly near the tectonic basins where two sets of faults intersect,or close to the NW-trending tectonic belt. The NE-NNE and NW-trending faults are a pair of conjugate sheer fracture planes characterized mainly by lateral strike-slip movement under the action of the contemporary NEE-directed near-horizontal principal stress. The NE-NNE faults belong to the inheritance fault,which control the regional geological tectonic pattern and its evolution,often large in size; while the NW ones mostly belong to newly-generated fault,and their size is usually related to the size of NE-NNE faults they conjugate with. The study shows that the moderate-strong earthquakes in the Liaodong peninsula are controlled mainly by the NE-NNE structures,and the seismogenic structures are basically the NW faults. Meanwhile,correlated with the size of the NW faults,the moderate-strong earthquake activities show a trend of decreasing gradually from north to south and from west to east,and the magnitude of them decreases roughly from M7～7.5 to M5.5～6 or so.