Abstract: In this paper, the characteristics of temporal and spatial distribution of the precursory anomaly before Yongdeng earthquake have been analyzed by using synthetical method. The analytical results show that the precursors of Yongdeng earthquake (M_S=5.8) are of the following features: large quantity, wide distribution, high density and obvious postseismic response. The temporal distribution is in groups, the spatial distribution is relatively stable, which may be related with such a pattern that the moderately strong earthquakes occurred in swarms in this area. This research result has been a pplied to them edium-term and short-term prediction of Tianzhu-Gulang earthquake (M_S=5.4) in 1996.

Key words: Precursory anomaly, Mid-term prediction, Short-term Prediction, Yongdeng earthquake