A　pulsatile　circulation　system　has　been　built　to　simulate　aortic　blood　flow.　The　system　has　both　upstream　and　downstream　compliances　and　resistances　to　simulate　the　elasticity　and　resistances　of　blood　circulation　system.　Influences　of　the　compliances　and　resistances　on　the　pulsatile　pressure　waveforms　have　been　systematically　studied　using　this　system.　We　found　that　in　absence　of　the　compliances　and　the　downstream　resistance,　it　results　in　an　oversize　negative　pulsation　to　the　pressure　waveforms.　The　downstream　resistance　hardly　affects　the　structure　of　the　pressure　waveforms,　whereas　the　mean　amplitude　of　pressure　increases　along　with　the　downstream　resistance.　The　compliance　can　reduce　the　peak　value　of　the　pressure,　which　is　unrelated　to　the　location　of　the　compliance　but　related　to　the　elasticity　in　the　system.　With　fixed　upstream　system　elasticity,　the　pressure　waveform　is　more　stable.