In　general,　residual　current　devices　(RCDs)　have　problems　such　as　protection　dead-zone　and　difficulty　in　threshold　setting.　A　new　method　for　identification　of　biological　electric　shock　(BES)　in　low-voltage　distribution　network　based　on　threshold　method　is　proposed.　Firstly,　the　total　residual　current　of　the　circuit　is　denoised　by　Kalman　filter,　and　then　two　threshold　methods　are　investigated　to　determine　the　electric　shock　(ES)　event　and　type　respectively.　Specifically,　the　first　threshold　consists　of　the　maximum　and　average　value　of　the　current　changes　in　the　previous　period,　which　is　an　adaptive　value　of　dynamic　change.　If　the　current　sampling　value　exceeds　the　threshold　for　10　times　in　total　within　5　ms,　an　ES　is　considered　to　have　occurred.　Then　considering　that　the　amplitude　of　the　waveform　of　the　first　three　periods　after　BES　has　the　characteristics　of　gradual　changes,　the　sampling　values　of　the　three　periods　are　recorded.　The　second　threshold　is　a　fixed　threshold　which　is　obtained　by　weighting　the　phase　point　changes　corresponding　to　the　second-period　and　the　third-period　waveforms,　and　then　the　specific　ES　types　are　distinguished.　The　proposed　method　is　implemented　on　hardware　devices　and　analyzed　in　various　common　ES　situations.　The　results　show　that　for　the　three　cycles　of　waveforms　collected　after　the　occurrence　of　grounding　or　ES,　the　accuracy　of　this　method　is　97.84%　and　the　recognition　time　is　2.07　ms.　In　addition,　based　on　the　analysis　of　the　actual　BES　data,　a　simple　digital　model　is　proposed　to　simulate　the　actual　biological　response,　and　it　can　be　of　great　help　in　the　subsequent　study　of　such　problems.　　©　1986-2012　IEEE.