Abstract: The typical interferences in the geoelectric data observed by Tongzhou, Yanqing and Changping seis-mostation since 2004 are identified and classified.They are mainly environmental interference, electrical current disturbance, spatial magnetic field interference, observation system itself interference (replacing electrode or arrester).The results indicated that geoelectric field observation is very sensitive to the local environment change, electrical and magnetic environment change and observation system change, so we must eliminate all interfer-ences when using geoelectric field data.