For　the　single-phase　high-impedance　ground　fault　(HIF)　in　resonant　grounding　system,　single　characteristic　quantity　fault　information　is　not　obvious,　and　there　is　a　significant　difference　in　transient　zero-sequence　currents　between　fault　line　and　non-fault　line.　A　new　method　of　single-phase　HIF　line　selection　based　on　improved　Euclidean-dynamic　time　warping　(E-DTW)　distance　is　proposed.　Firstly,　the　similarity　matrix　of　the　transient　zero-sequence　current　waveforms　after　two　cycles　of　fault　is　obtained　by　combining　dynamic　time　warping　(DTW)　distance　with　Euclidean　distance,　and　a　comprehensive　similarity　coefficient　of　each　line　waveform　is　constructed.　Then　fuzzy　C-means　clustering　(FCM)　algorithm　is　used　to　realize　single-phase　HIF　line　selection.　In　addition,　because　similarity　of　the　non-faulty　line　transient　zero-sequence　current　waveforms　caused　by　the　difference　of　line　parameters　in　engineering　application　is　low,　the　original　waveform　is　preprocessed　to　improve　reliability　of　the　line　selection　method.　Simulation　results　show　that　the　proposed　method　is　effective　for　both　single-phase　HIFs　and　various　ground　faults.　Even　in　the　extreme　cases,　such　as　noise　interference,　asynchronous　sampling,　polarity　reverse　connection　of　zero-sequence　current　transformer,　and　two-point　high-impedance　grounding,　the　line　selection　method　is　still　strongly　robust　and　fault-tolerant.　©　2020,　Power　System　Technology　Press.　All　right　reserved.