Abstract: Based on the results of focal mechanism solutions and statistical analysis for 17 deep-focus earthquakes (h>350km, M>4.0) occurred in the western part of the Sea of Japan, the dominant directions of the earthquake generating stress field are found as follows: the directions of the compressive and tensile principal stress axes are 85°—110° and 255°—280° respectively.According to the relation between the seismic activity of strong earthquakes of North and Northeast China and that of deep-focus earthquakes of the Sea of Japan, a time and distance regressive equation of seismic migration has been obtained. Using this result, it is probably helpful for predicting future earthquakes in northeastern China.