Employing the mobile gravity data from 2009 to 2013 as the foundation,mobile gravity observation data of the middle region of North China from 2009 to 20l3 were analyzed,and time-space dynamic evolution characteristics of the gravity field were studied.The change of the gravity field is closely related to the tectonics of active faults.The resulting gravity data showed that the changes in gravity anomalies in North China are severe.In the northern portion of the Shanxi graben zone,centered at the border region in Shanxi,Hebei, and Inner Mongolia,the gravity variation showed a large area of negative anomalies.The entire survey area showed a large area of negative changes in the local area with a gravity gradient formation,which reversed the recent changes,indicating a further increase in regional seismic hazards.This potential guide to earthquake prediction has important practical significance.