Abstract: Earthquake monitoring in reservoir head region of TGP started 46 years ago,which is rare in the hydraulic electricity history all over the world. The synthetic analysis for all of the earthquake monitoring data indicates that before the reservoir retained water, reservoir head region was a typical weak earthquake region in which earthquake did not happen frequently, and the intensity of the earthquake was low. Its epicenter primarily located in east side and west side of the Zigui Basin, It mostly belonged to the natural tectonic earthquake respecting the cause. After retaining water, the frequency of seismicity increases significantly, the strength keeps in its background level before retaining water, the strongest earthquake is only ML2.4. The space location of the seismicity has changed greatly after retaining water, the seismicity primarily locates in reservoir region from Niukou in Badong to Peishi in Wushan.?

摘要： 三峡工程库首区地震监测至今已有46年，在世界水电史上也是罕见的。46年的地震监测资料综合分析表明，蓄水前库首区是一个典型的低频度、强度小的弱震区，其震中在空间上主要分布于秭归盆地的东西两侧，其成因大部分属于天然构造地震。蓄水后，地震活动频度大幅增加，强度保持在蓄水前的本底水平，最大地震仅为ML 2.4级。地震活动的空间分布与水库蓄水前相比，有较大的变化，其地震活动主要分布于巴东牛口至巫山培石库段。