Abstract: In this paper, we presented the linear relation between tide factor and Love number h₂. The v ariational range of h₂ is 7.5 times larger than anomalies of tide factor of body strain prior to earthquakes. The changes in tide factor of O₁ wave of shearstrain is well consistent with that in M₂ wave tide factor of body strain prior to earthquakesat Changping Station. It may be one of the useful methods for extracting anomalies before earthquakes to study the change of tide factor of borehole strain.

Key words: Tide factor, Body strain, Shear strain, Anomaly