Ideality　factor　can　reflect　the　current,　the　carrier　leakage,　and　the　phenomenon　of　non-radiative　recombination　in　light-emitting　diode　(LED).　For　the　problem　of　ideality　factor　from　current　report　about　GaN-based　LED,　the　value　of　ideality　factor　n　is　calculated　by　using　the　I-V　curve　fitting　of　high　voltage　LED.　And　the　relationship　between　the　ideality　factor　and　the　number　of　units　is　series　in　12,　19,　51　and　80　V　GaN-based　high-voltage　LED　are　discussed.　In　addition,　the　relationship　between　ideality　factor　and　spectral　half　width　(FWHM)　is　analyzed,　and　the　impact　of　current　crowding　effect　on　the　ideality　factor　is　also　studied.　Results　show　that　the　ideality　factor　n　increases　nearly　linearly　with　the　number　of　units　in　series,　indicating　that　the　ideality　factor　n　of　high　voltage　LED　is　composed　of　its　series　units.　It　is　a　valuable　result　for　understanding　the　ideality　factor　of　GaN-based　high　voltage　LED.