Based on four-phase geomagnetic vector data from 2005 to oft-com:office:smarttags" />2008 in Jiangsu-Shandong-Henan-Anhui region, the F, D, I component geomagnetic anomalous fields at the four phases are established. By analyzing the time-space dynamic evolution characteristics of geomagnetic field of the middle segment of Tan-Lu fault zone, it is found that the F, D, I component geomagnetic anomalous fields in this region have greatly changed and even reversed before and after Jiangxi earthquake in November 2005, but from Spring of 2007 to Spring of 2008 the geomagnetic anomalous field distribution in this region basically keeps steady.oft-com:office:office" />