College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China

The division of regional gravity field and local gravity field is one of the important steps in gravity data interpre-tation. On the basis of inspecting common methods in dividing regional gravity field and local gravity field by spatial domain and frequency domain, the authors propose multi-ring median filteringmethod. This method builds multiple rings using calculated point as the center, calculates the median and the mean variance of each ring, and process filter under presettable conditions to take the median which meet the condition of ring as the point of regional field value and get local field by removing regional field in gravity anomaly. The results of theoretical model and actual data show multi-ring median filtering method is adaptable, which carrying out smaller field distortion, and the method can well retain the boundary characteristics between anomalies.