对郯庐断裂带及两侧的山东、辽宁、河北、江苏、江西等地区1966 ～ 2005 年发生的24次中强以上地震的前兆观测异常，从异常持续时间、空间分布、时空相关性、异常形态、幅度特征、异常种类和可靠性等方面进行了系统的统计和分析，结果表明:①7 级和6 级地震中期异常最多，短期异常其次，临震异常最少。5 级地震短期异常最多，其次是临震异常，中期异常最少。②异常具有阶段性特征，部分中期和短期地震前兆异常在发展过程中出现了短期或临震异常。③异常发展具有准同步性，越临近发震，异常发生转折的项目越多。④异常主要出现在震中距100km 范围内，在空间上具有相对集中性，且震中距越小，异常台项比越高。⑤异常空间分布与构造走向比较一致，显示出较好的相关性。⑥异常持续时间与震中距之间没有显著的相关性。⑦震级越大，同一观测手段的异常幅度相对越大。⑧流体测项异常最多，其次是形变、电磁测项。⑨不同学科的异常均表现为中、短期异常为主，少数为短临异常。⑩流体、形变和电磁学科较可靠异常数量均约为可靠异常的1 倍。

This article counted and analyzed the duration，spatial distribution，form，range，type and reliability of abnormities based on the abnormity observation of earthquake precursors of 24 mezzo forte earthquakes at Tanlu cross-fault and its bilateral areas such as Shandong，Liaoning， Hebei，Jiangsu，Jiangxi provinces from 1966 to 2005． Results showed that: (1) For M1. 7 and M6． 0 earthquakes， medium-term abnormities occurred most often， short-term abnormities occurred sometimes， and impending earthquake abnormities occurred rarely． For M5. 0 earthquakes，short-term abnormities occurred most often，impending earthquake abnormities occurred sometimes and medium-term abnormities occurred rarely． ( 2 ) Precursory abnormities are periodical，part of the medium-term and short-term abnormities showed short-term and impending earthquake abnormities during its development． ( 3 ) The development of precursors showed prospective synchronism; the closer to earthquakes，the more changes of directions of abnormities． (4) Abnormities mainly occurred within 100km2 distance of the epicenter． It showed relative centrality in space and the shorter the distance of epicenter，the higher the abnormity to total observation ratio． ( 5 ) The space distribution and the structure trend of abnormities were relatively correlated． It showed good interdependency with the structure． ( 6 ) There was no significant correlation of the duration of the abnormities and the distance of epicenter． (7) The higher the magnitude of the earthquake，the bigger the range of the abnormities with the same observation approach． (8) Fluid subject showed the most abnormities，followed by deformation and electromagnetism subjects． ( 9 ) For all different subjects，medium-term and short-term abnormities made up the majority and short-term and impending earthquake abnormities were the minority． ( 10 ) For fluid，deformation and electromagnetism subjects，the relative reliable abnormities were about double the reliable abnormities．

国家重大科技支撑项目(2012BAK19B04-05-02)和中国地震局地震科技星火计划项目(XH13015)资助