Duringtheperiodof1999~2002,theChineseseismologistsmadeaseriousofdevelopmentsinthestudyonseismicsourcesincludingobservations,experimentsandtheory.Inthefieldofobservation,themethodsoftheaccuracylocationofearthquakesources,theinversionofseismicmomenttensorandthemechanismofearthquakesourceareimprovedanddeveloped.Alotofimportantearthquakeeventsarestudiedbyusingthesemethods.Theruptureprocessesoftheseeventsareinvertedandinvestigatedcombinedwiththelocalstressfieldsandthetectonicmomentbyusingthemeasurementsofsurfacedeformation.Inthefieldsofexperimentsandtheory,manydevelopmentsareobtainedincauseofseismicformation,conditionofstressandtectonics,dynamicsofearthquakerupture,rockfractureandnucleationofstrongearthquakes.