Abstract: The southwestern system of the Taihang mountain-front fault includes Shijiazhuang city and its adjacent area, which is located in the southwestern Capital Circle and in the cross area between Taihang Uplift and North China Basin, the geological structure is complicated in the area. Based on the SAM method and data (2002.1~2005.8) from Capital Circle Seismic Network, the seismic anisotropy in southwestern Capital Circle is obtained. It is shown that the average polarization of fast shear-wave is consistent with the regional maximum horizontal principal compressional stress, it is an efficient tool to depict regional stress field. The average time delay of slow shear-waves is lower than in northwestern and southeastern Capital Circle. The fast shear-wave polarizations at stations are influenced both by the regional stress field and by the local tectonics with NNE striking direction. The shear-wave splitting parameters at Jingxing station (JNX) are different from the station nearby; more data are needed to explain the phenomenon.

Key words: Shear-wave splitting, Polarization, Time delay, Taihang mountain-front fault