Based on the event waveform data and its observation report of the 2011 Ruichang-Yangxin MS4.6 earthquake sequence processed by the double-difference method, waveform cross-correlation and coda wave interferometry, two groups of repeating earthquakes (cc≥0.920, recorded by station Huangmei and station Jiujiang) can be obtained: D1 (2011-09-11 05:44 ML2.3 and 2011-10-24 08:06 ML2.2) and D2 (2011-09-18 07:06 ML2.8 and 2011-10-24 08:06 ML2.2). It could be found that the velocity of early S wave coda increased within 1.5 months (2011-09-11—10-24) in source region after the MS4.6 Ruichang-Yangxin earthquake.
