Abstract: Based on summarization of the previous results and used them for reference, the ob­servat10nal data from Western Yunnan and Beijing regional gravity networks for nearly ten years are recalculated and re analyzed by using a new relative datum of regional gravity field and a graphic technique. The research on the precursor anomaly indexes of spatial distribution changes of gravity fields suited for the Western Yunnan and Beijing regional gravity networks is presented by means of studying the spatial distribution changes of re gional gravity fields and their relationship with moderately strong earthquakes. The future earthquake trends in the Testern Yunnan and Beijing regional gravity network regions and their neighbouring areas are estimated. The conclusion in this paper can be provided as a reference for analyzing the observational data of the same type of regional gravity net­works.

Key words: Precursor information, Regional gravity field, Relative datum, Anomaly index