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Based on the focal mechanism solution database established by collecting 37 years initial motion of small earthquakes (1970~2006), the space‐time evolution characteristics of small‐earthquake integrated mechanisms in Shanxi fault zone are studied in this paper. The results indicate that small‐earthquake integrated mechanisms in Shanxi fault zone are mainly dominated by strike slip normal faults; those at two ends of the zone are dominated by extension tectonics and those in the central region by shearing. The difference between the stress field of Huabei and the regional stress fields of Xinding and Taiyuan Basins is very large. The relationship between horizontal motions and earthquake activities in Shanxi fault zone is analyzed according to the 12 stages of re‐measuring data of GPS monitoring network along the Shanxi fault zone (1996~2007). The results indicate that the Shanxi fault zone now is mainly controlled by compressional stress field along NWW‐SEE direction and tensile stress along NNE‐SSW. One obvious stress disturbance occurred during the period of 1998~1999, which was stronger in the north and weaker in the south. This was followed by Datong‐Yanggao M5.6 earthquake on 1st Nov.1999.

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