Abstract: A Grey prediction system GM(1, 1) model has applied to process the monthly average value of the geoelectrical station data, which are within a epicental distance of 120Km and have longterm and continuous observation history and normal background.The results have shown: the data of Baodi, Chanli, Xiji, Qinguang etc stations present negative anomalous before the main shock in different level; Baodi station behaves the an omalous pattern overlap before Tangshan and Haicheng earthquake; Xiji and Qinguang stations have independent anomalous style before two main shock; Changli station gives obvious decrease before Tangshan earthquake; but Mafan station has no anoma-lous change.Besides the consistent results with that obtained before, we suggest some new opinion.These demonstrate that the Grey prediction system is available to the processing of the geoelectrical data.