A　new　method　which　constructs　time-domain　network　analytic　system　by　using　of　nose-to-nose　technology　and　Agilent　86100　broadband　sampling　oscilloscope　is　put　forward　in　this　paper　based　on　the　basic　theory　of　nose-to-nose　calibration　technology.　Coaxial　adapter　and　cable　whose　nominal　bandwidth　is　50　GHz　have　been　measured　by　this　system.　Then,　time-domain　characteristics　(　e.　g.　impulse　response,　step　response,　rise　time　and　overshoot)　and　frequency-domain　characteristics　(amplitude　response,　phase　response　and　bandwidth)　could　be　obtained　by　digital　signal　processing.　Swept-sine　method　comparison　experiments　verified　that　the　method　is　effectual.