When　single-phase-to-ground　fault　occurs　in　resonance-grounding　system,　the　transient　zero-sequence　current　of　each　line　in　resonant　grounding　system　is　nonlinear　and　non-stationary,　and　there＇re　many　differences　between　the　transient　zero-sequence　current　waveforms　of　faulty　line　and　those　of　normal　lines.　On　this　basis,　a　fault　line　selection　method　using　mutual　correlation　cluster　of　grounding　fault　waveforms　based　on　improved　DTW(Dynamic　Time　Warping)　method　is　proposed.　The　ACCM(Amplitude　Correlation　Coefficient　Matrix)　of　transient　zero-sequence　current　waveforms　of　different　lines　within　half　cycle　after　fault　is　obtained　via　improved　DTW　method.　By　combing　the　PCCM(Polarity　Correlation　Coefficient　Matrix)　of　transient　zero-sequence　currents　with　ACCM,　the　CCCM(Complex　Correlation　Coefficient　Matrix)　is　constructed,　which　represents　the　amplitude　and　polarity　information　of　transient　zero-sequence　currents.　Then　the　faulty　line　is　selected　by　FCM(Fuzzy　C-Means)　cluster　method　without　setting　threshold.　The　simulative　results　of　noise　interference,　two　points　grounding　fault,　arc　fault　and　asynchronous　sampling　show　that　the　proposed　fault　line　selection　method　is　immune　to　possible　influence　factors　in　engineering　application,　the　proposed　method　can　achieve　reliable　faulty　line　selection.　©　2018,　Electric　Power　Automation　Equipment　Press.　All　right　reserved.