Abstract: Following the Airy-Heiskenen model for is static gravity, we have used the topographic elevation to make up a map showing the isostatic gravity anomaly in the study region, bounded by 37-41 N and 115-120 E, and another map (11) for the same purpose. It is shown in the map that there is a greater fluctuation in Bouguer anomalies in some parts of the study region, the maximal value (60 mgal) in the Daxing area, the minimal one ( - 25; - 15mgal) reapectively in the Yumengshan mountain north of Miyuan and Yuairu and in the Wuqing area. There come the gravity high, gravity low and the gravity -gradient zone one after the other in this region. The regional isostatic anomalies are of the positive value, with the exception of the Tangshan-Luanxi area in front of the Yanshan mountain and the converging part of the Taihangshan mountain, west of Beijing, with the Yanshan mountain.Given in this papper has been a preliminary discuss on the relationship of what is drawn from the map with the geological structures, recent tectonic motion and the seismic activity. It is believed that the regional isostatic anomalies may represent characteristics by the Cenozoic geotectonic configuration, with little variation in Bouguer value throughout the region that is backgrounded with the normal anomalies.From the tectonic motion, it can be inferred that the gravity iaostatic adjustment may have been responsible for descending of the region. That is in an agreement with the regime of the recent tectonic motion and the groud deformation going since the Quaternary. Calculations indicate that the isostatic adjustment would prevail in the recent tectonic motion at least in 10 years. Statically, It can be seen that the earthquake may tend to occur in the gravity gradient zone with anisostatic anomalious value ranging from 30-40 mgal.