Abstract: In this paper the precursor anomaly terms of more than 80 earthquake examples from 1987~1999 in China' continent are applied for statistical study. The space-time variation property and synthetical characteristics of precursor anomaly terms are investigated for liquid, deformation and electromagnetism before strong earthquakes. The signs of precursor anomaly transition from the medium term to the short-imminent term, the field and source omen, relativity among precursory variation, nonuniformity of omen distribution and the coincidence of precursors with seismic activity are emphasized. On the basis of above-mentioned facts, the synthetic determination index is put forward; also study on prediction application for strong earthquakes has been tried by using the probability gain methods.

Key words: Precursor anomaly statistics, Property of short-and imminent term, Synthetic determination