Abstract: The observation data of cave deformation (ground tilt)are processed with some effective parameters and methods in anomaly judgment.Combined with the analysis to some earthquake examples,two methods of extracting seismic anomalies from cave deformation data suitable in Shanxi province are obtained.They are the method of extracting anomaly information from multi-stations and the method of eliminating yearly period with correlative distance average.The prediction effect was examined by statistics method;the R-values of the two methods is 0.40 and 0.24 respectively.The R-value of the method is relatively high.