The　delamination　of　epoxy　coating　on　X80　pipeline　steel　was　evaluated　under　various　stray　alternating　current　(AC)　interferences　(0-300　A/m(2)).　Qualitative　and　quantitative　analyses　were　carried　out　using　scanning　electrochemical　microscopy　(SECM),　electrochemical　impedance　spectroscopy　(EIS),　and　three-dimensional　digital　microscopy.　The　results　show　that　the　SECM　current　is　directly　proportional　to　the　soaking　time　and　applied　current　density.　The　variation　in　SECM　current　curve　shape　indicates　the　delamination　distance　of　epoxy　coatings　at　the　defect　area.　The　depths　of　corrosion　pits　at　50,　100,　and　300　A/m(2)　stray　currents　were　140,　160,　and　240　mu　m,　respectively.　The　corrosion　pits　also　became　wider　with　increasing　current　densities.　With　increasing　stray　AC　densities,　both　the　coating　delamination　and　pit　depth　became　more　severe　at　the　same　soaking　time.　The　EIS　results　show　that　the　change　in　impedance　was　not　significant　without　stray　current,　whereas　the　impedance　first　decreased　and　then　increased　when　stray　current　was　applied.　These　results　are　consistent　with　the　SECM　measurements.