Abstract: It is well-known that the earthquake is result from the accumulation and release of strain energy. There has not been quantitative analysis and description for a long time. On the basis of correlation between observed items, the index of anomaly intensity has been researched, and the intensity field evolution images also have been constructed. It is demonstrated that the most earthquakes were occurred during anomaly quiescence and far from the anomaly areas after the regional anomaly concentration. The close relation between anomaly intensity and accumulation of strain is shown in this paper.

Key words: Key w ords: Anomaly intensity field, Evolution, Earthquake precursor