Basedondatacollectedfromatemporalseismicnetwork,andinadditiontothedatafromsomenearbypermanentstations,weinvestigatethevelocitystructureandseismicityintheRongchanggasfield,wheresignificantinjection-inducedseismicityhasbeenidentified.First,weusereceiverfunctionsfromdistantearthquakestoinvertdetailed1-Dvelocitystructuresbeneathtypicalstations.Then,weusethedouble-differencehypocenterlocationmethodtore-locateearthquakesofthe2010ML5.1earthquakesequencethatoccurredintheregion.There-locatedhypocentersshowthatthe2010ML5.1earthquakesequencewasdistributedinasmallareasurroundingmajorinjectionwellsandclusteredmostlyalongpre-existingfaults.Majorearthquakesshowafocaldepthlessthan5kmwithadominantdepthof～2km,adepthofmajorreservoirsandinjectionwells.Wethusconcludethatthe2010ML5.1earthquakesequencemighthavebeeninducedbythedeepwellinjectionofunwantedwateratadepth～3kmintheRongchanggasfield.
