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在张北－尚义地震区震前已有大地电磁资料测点（５１１点）进行了两次重复观测，在震中区测点（ＭＭＣ点）进行了连续４昼夜的观测。测量结果显示：（１）与震前资料相比，５１１测点沿电性构造走向方向（ＮＮＷ）在０．２～４ｓ周期范围内的视电阻率减小，垂直走向方向的视电阻率增大；（２）ＭＭＣ测点两个方向在０．２～１０ｓ周期范围内的视电阻率随测量时间逐渐增大；（３）５１１测点两次重复观测和ＭＭＣ的观测可能都反映出震后电阻率正在逐渐恢复。此外，还对地震前后地下结构的变化进行了分析。初步推测，观测到的电阻率变化是由于地下流体活动引起的。
In the Zhangbei-Shangyi earthquake zone, there were two repeated observations of the MT data (511 points) before the earthquake and four consecutive days of observation at the epicenter measurement point (MMC point). The results show that: (1) Compared with the pre-earthquake data, the apparent resistivities of the 511 measuring point along the electrical structural direction (NNW) in the period of 0.2-4s decrease and the apparent resistivity in the vertical direction increases (2) The apparent resistivity in the period of 0.2 ~ 10 s in both directions of MMC measuring point gradually increases with the measuring time; (3) The repeated observation of 511 measuring points and the observation of MMC all may reflect the shock After the resistivity is gradually restored. In addition, the changes of underground structures before and after the earthquake were also analyzed. It is initially hypothesized that the observed change in resistivity is due to subsurface fluid activity.