The　nose-to-nose　(NTN)　calibration　theory　is　introduced　by　Ken　Rush　and　Dr.　Jan　Verspecht　in　1994　after　several　years　study,　it　is　an　accurate　method　to　determine　the　impulse　response　of　broadband　sampling　oscilloscopes.　The　method　is　based　on　the　hypothesis　＂sampler＇s　kick-out　pulse　equals　oscilloscope　impulse　response＂.　We　have　studied　the　theory　from　stimulation　to　experiment.　In　this　paper,　the　kick-out　pulse　and　the　response　of　the　kick-out　pulse　are　presented　using　PSPICE　and　MATLAB　software.　And　two　same　Agilent　86100　types　are　connected　to　obtain　the　response　waveform　of　the　kick-out　pulse.　Although　data　processing　is　not　perfect　yet,　simple　introductions　are　given　in　this　artical.