High-power　blue　light-emitting　diodes　were　biased　by　negative　Human-Body-Mode　electrostatic　discharge(ESD)　with　-200,　-400,　-600,　-800,　-1100　and　-1500　V.　The　electrical　and　optical　parameters　of　the　LED　were　measured　before　and　after　ESD　stressing.　The　failure　mechanisms　resulted　in　by　ESD　stress　were　analysised　after　each　ESD　stress.　The　LED　had　evident　soft　breakdown　due　to　the　generation　of　defect　in　active　region　and　cladding　layers　after　ESD　stressing　at　-200,　-400,　-600　and　-800　V.　However,　when　the　device　was　biased　to　-1100　V　and　-1500　V,　high　leakage　current　of　the　LED　appears　and　50%　degradation　of　light　output　than　before　stressing.　The　reason　is　the　generation　of　melting　thread　in　active　region　that　made　LED　cannot　emit　light.　In　addition,　a　simple　and　effective　protection　circuit　for　ESD　is　proposed.