In　order　to　investigate　their　electrical　characteristics,　high-voltage　light-emitting-diodes　(HV-LEDs)　each　containing　four　cells　in　series　are　fabricated.　The　electrical　parameters　including　varying　voltage　and　parasitic　effect　are　studied.　It　is　shown　that　the　ideality　factors　(IFs)　of　the　HV-LEDs　with　different　numbers　of　cells　are　1.6,　3.4,　4.7,　and　6.4.　IF　increases　linearly　with　the　number　of　cells　increasing.　Moreover,　the　performance　of　the　HV-LED　with　failure　cells　is　examined.　The　analysis　indicates　that　the　failure　cell　has　a　parallel　resistance　which　induces　the　leakage　of　the　failure　cell.　The　series　resistance　of　the　failure　cell　is　76.8　Omega,　while　that　of　the　normal　cell　is　21.3　Omega.　The　scanning　electron　microscope　(SEM)　image　indicates　that　different　metal　layers　do　not　contact　well.　It　is　hard　to　deposit　the　metal　layers　in　the　deep　isolation　trenches.　The　fabrication　process　of　HV-LEDs　needs　to　be　optimized.