Abstract: 25 great earthquakes (M≥6.8) in China's mainland since 1970 are studied by using the prediction approach of state vector in this paper. The results show that apparent anomalies occur within 3 years before 19 earthquakes among 25, of which apparent anomalies occur within 60 days before 9 among 19. This implies that the state vector could be used as a kind of methods for mid-term and short-term earthquake prediction. The results also show that the module of state vector is more sensitive than other parameters stated in this paper. The results show at the same time that there are different best scan zones relative to the same magnitude earthquakes occurred in different locations. The causes of these phenomena are discussed in this paper.

Key words: China's mainland, State vector, Characteristics of anomaly, Earthquake prediction