Abstract: We review cross-fault deformation anomaly before the earthquake cases recorded in China Earthquake Cases series and periodicals in North China. We analyze the features of these anomalies in different regions across North China. In 1~3 years prior to the three M6 or lager earthquakes, there were some 10 to 30 cross-fault deformation anomalies in the Capital region, of which more than 80% abnormal sites are located 100 km or further away from the epicenter; 70% to 80% percent of the abnormal items lasted longer than one year and notebly the accelerating or transition; anomal amplitude were concentrated in 1~3 mm; the quakes occured either in development of anomalies or the recovery period of after the abnormies number reached the peak. As the magnitude of events decreased, anomalies increased in the near-field (within 100km from epicenters). For M5 earthquakes, 2~8 items of anomalies appear in both near-field and far-field. For M4 earthquakes, there are only 1~2 items of anomalies and are mainly distributed in the near-field.

Key words: Cross-fault deformation, Precursory anomaly, China Earthquake Cases, North China