In this paper the source mechanisms of 33 earthquakes and the P axis-trends are obtained whichoccurred in JiangSu and its neighborhood

by using the Snoke’s method of swing ratio and the digital wavedata recorded by JiangSu net and SanDong net. The result indicates that some abnormal earthquakeswhose P axis-trends are smaller than 100° occurred in about two months before ML5.1 earthquake in thenorthern Sunken region of the Yellow Sea or remarkable event occurs in the Yangtse River intake region;and no abnormal earthquakes occur whose P axis-trends are smaller than 100° and also remarkable eventsor moderate earthquakes occur in the YanCheng neighborhood and its adjacent sea area. These obviouslydemonstrate that the P axis-trend of source may be useful for the short-term and imminent prediction.which

however

is not in agreement with the phenomenon of great seismic events. The phenomenon ofthe two events with P axis-trends smaller than 100° agrees well with that of the abnormal gravity withinthe MaoSan fault area

which shows that the MaoSan fault were active around the year of 2002.