Abstract: Based earthquake data recorded by the Anhui seismic network, using waveform analysis and inversion, we calculated small to moderate earthquake apparent stresses in the south part of the Tanlu fault belt and adjacent areas, analyzed their variation characteristics in time and space, discussed the corresponding relationship with earthquake moment and source parameters.The results show: ① Using earthquake source spectrum data, the obtained apparent stress value in the south part of Tanlu fault belt and adjacent areas is between 0.05～0.9 MPa, averaging 0.20 MPa, which is the background stress level of the region; ② Temporal change shows apparent stresses continued to present abnormally high values before Huang Hai M_L5.1 earthquake, Jiangxi Jiujiang M_L6.0 earthquake and Henan Taikang M_L5.0 earthquake, to be normal after earthquake. But after Jiangxi Jiujiang magnitude 6 earthquake, apparent stresses have again a high value anomaly, subsequently Anhui Dingyuan M_L4.7 earthquake happened, to a certain extent show that the high level of apparent stress in the south part of the Tanlu fault belt and adjacent areas have a good corresponding relationship with strong earthquakes in East China; ③ Spatial distribution shows high value area of apparent stress is relevant to the seismic radiation energy higher area, mainly lied in Jiashan-Chuzhou section and Lujiang county nearby,where Dingyuan magnitude 4.7 earthquake and Anqing magnitude 4.8 earthquake happened in succession; ④ It is not obvious that apparent stress increases with earthquake moment,corner frequency basically has a negative correlation with earthquake moment.

Key words: Tanlu fault belt, Apparent stress, Earthquake moment, Temporal and spatial characteristics