Abstract: This paper analyzes interference factors in geoelectric field observation,such as observation system fault,electric resistance measurement,lightning,precipitation and human activities.These interference factors can lead to data quality decreasing.Relationships between each observation items are also discussed and method to discern anomaly is put forward in this paper.The results indicate that observation data in Xinyi station can reflect the actual change of the observation site;if the interference factors can be eliminated,the precision of the data is quite high.