Abstract: Based on the correlation of seismicity between the edges of the continental plate of China and its interior the main part of seismicity and the period of high seismicity in China will be determined. In this parer making use of seismicity information of large scale area and long time period,a synthetical evaluation method to estimate the time,location and magnitude of future earthquakes in the monitored area has been developed. There are three parts in this paper:1.Prediction of the earthquake magnitude. Five seismicity indices to determine the strength of future earthquake have been studied in detail. Applying fuzzy synthetical evaluation method that is the weighted average type to five indices,the magnitude of future earthquake in the monitored area can be more accurately given.2.Prediction of the earthquake location. Two indices,A_yi——frequaency of abnormalb-value and b_yi——average of abnormal b-value,were defined for the scanning unit. Adoptingsynthetical analyses of spacial distribution of two indices the location of future earthquake can be approximately estimated.3.Prediction of earthquake occurring time. The time of lacking earthquakes T₁ and the rising time of b-value T_bu were applied to describe quiet process before earthquake. After making fuzzy synthetical evaluation for the magnitude of earthquake we may infer the time of occurrence of future earthquake according to the indices T₁ and T_bu.The results of summarizing nine earthquakes have shown that the method in this paper will give quantitative and practical indices in earthquake prediction. It can be applied in the evaluation of earthquake trend and short and medium period earthquake prediction.