The hemodynamic features of the involved blood vessels in 11 patients with Budd-Chiari syndrome were studied by duplex Doppler SODography.The results showed that there were abnomalities in the direction,velocity,nature and spectral patterns of the blood flows of the involved blood vessels,It is suggested that duplex Doppler ultrasound examination can nonmvasively obtain the hemodynarnic data of inferior vena cava,hepatic veins and portal vein and is very valuable in the clinical analysis,diagnosis,treatment and evaluation of the theurapeutic effect of Budd-Chiari syndrome.