Abstract: The far-field precursory anomalies, super long-term precursory anomalies lasting for 8~20years, and the judging methods of the anomalies are analyzed in this paper. Them eaning of far-field anomalies, the implication of precursory curves and the correlation between the earthquake and the complexity of earthquake prediction are also discussed. This aspect of discussion is beneficial to the further research on physical features of precursors and the practice of earthquake prediction.

Key words: Precursory anomaly, Earthquake prediction, Synthetic analysis