Abstract: Based on the Tangshan deformation data since 1984, the autoregression (AR) model and spectrum analysis with Daniell moving windows are applied. The order of AR model is compared around the time of Tangshan local earthquakes (M_L≥5.0)and strong earthquakes in North China(M_L≥6.0). The result shows that the orders based on the analysis on baseline data are larger before the earthquakes than those after the earthquakes. So are the orders based on the analysis on leveling data excepting the 1995 Tangshan earthquake. The spectrum analysis shows that the main spectrum is about 2~11 days and the spectrum is more plentiful before earthquakes than that after earthquakes. The variation is clearer in baseline spectrum than in the leveling one. However, the yearly spectrum is unclear in the spectrum analysis, which needs further study.

Key words: Tangshan seismic station, Deformation data, Daniell, Regional seismicity