When　the　bandwidths　of　oscilloscopes　are　similar,　three　different　broadband　sampling　oscillos-　copes　can　be　calibrated　by　＂Nose-to-Nose＂　calibration　procedure.　So　far　the　report　that　＂Nose-to-Nose＂　calibration　procedure　is　applicable　or　not　when　bandwidth　differences　are　relatively　large　has　not　been　found.　In　this　paper,　simulations　were　firstly　performed　on　＂Nose-to-Nose＂　calibration　procedure　when　bandwidth　of　oscilloscopes　differ　by　one　time,　then　broadband　sampling　oscilloscopes　which　bandwidth　are　50GHz　and　26.5GHz　were　studied　by　＂Nose-to-Nose＂　calibration　procedure.　These　results　all　indicate　that　＂Nose-to-Nose＂　calibration　procedure　is　also　applicable　when　bandwidth　differences　are　relatively　large.