Electrical　parameters　degradation　of　the　650V/30A　E-mode　GaN　HEMT　under　repeated　short　circuit　(RSC)　impacts　have　been　investigated.　The　repeated　short-circuit　impacts　conditions　are　as　followes:　short　circuit　voltage　is　100V,　gate　pulse　voltage　is　5V,　pulse　period　is　0.5S,　and　the　pulse　duty　is　6ppm.　The　number　of　short-circuit　impacts　is　100,　300,　500,　1k,　5k　and　10k　times　respectively.　After　short-circuit　impact,　the　threshold　voltage　Vth,　the　static　on-state　resistance　Rons　and　the　dynamic　on-resistance　Rond　are　measured.　The　test　results　show　that　all　of　these　parameters　have　been　increased　with　the　increase　of　the　RSC　impacts　number.　The　increase　rates　of　Vth,　Rons　and　Rond　are　23.7%,　9.8%　and　10.8%　respectively.　After　3　days　room　temperature　annealing,　both　Rons　and　Rond　almost　recovered　to　their　initial　value,　but　the　threshold　voltage　is　still　4.1%　larger　than　the　original　value.　©　2020　ACM.