Abstract:Geomagnetic low-point displacement anomalies occurred in North China from January 11 to 24, 2010, and the Hejin M4.8 earthquake occurred in the study area on January 24, 2010, after the ending of the anomalies. In this paper, the longitudinal effect of low-point time is removed by subtracting theoretical low-point time from measured low-point time, and the isoline whose low-point time is 0 h after removing the longitudinal effect is used as the low-point displacement boundary. The epicenter of Hejin M4.8 earthquake is located at the boundary of geomagnetic low-point time on January 16, 17, 19, and 22. The gradient value is used to describe the spatial distribution characteristics of low-point time. During the abnormal dates, there appears high gradient area in North China, whose gradient are greater than 1 h/(°), and the Hejin M4.8 earthquake is generally located at the edge of the high gradient area.