Based on the data of M≥6.0 earthquakes in Chinese mainland from 1975,in a certain scan time and scan radius from the epicenters,10 seismic parameters with clear physical significance and independence are choosed as objects to research the precursor symbol of the seismic parameters near epicenter area before strong earthquake.The result shows that the average corresponding ratio of precursor anomalies in 15 events in southwestern China is 0.77,the ratio in 10 events in northern China is 0.70 and in 18 events in northwestern China is 0.69.So this three numbers can be used as the precursor symbol of seismic parameters in each above rigions.