Abstract: This paper has analysed and studied the variational characteristics of groundwater level anomalies of Inner Mongolia precursory monitoring notwork within the range of 300 km around the epicenter of the Zhangbei M_S6.2 earthquake occurred on January 10,1998.The result showed that there were certainly anomalies of groundwater level before and after the Zhangbei M_S6.2 earthquake.By using the medium-short term and impeading earthuquake prediction methods of hydrochemistry and grou nd-water level,the relationship between the Zhangbei M_S6.2 earthquake and the grouped hydrochemical anomalies has been analysed and studied.the testable forecaste in midium-short term for the Zhangbei M_S6.2 earthquake was made.The occurrence time of the Zhangbei M_S6.2 earthquake was in accordance with the judging result in this paper,and it is pointed out that the anomalies was a precursory reflection for the Zhangbei M_S6.2 earthquake occurred on January 10,1998.