A new device that allows noninvasive measurement of venous pressure has been invented in our laboratory and tested for its feasibility and validity. The device consists of four parts: 1. the air infusion system; 2. the pressure sensor gauge; 3. signal transducer and data processing system 4. the fixing apparatus. The correlation between noninvasive pressure and invasive pressure has been studied in vitro test on a saphenous vein model and in vitro test on dog's portal venous system. In vitro and vivo study, an excellent correlation between noninvasive pressure and invasive pressure was obtained(r = 0.99, P < 0.0005; r = 0.97, P < 0.005). These data suggest that the new device allows a noninvasive measurement of venous pressure especially for the large veins such as vena cava, venae pulmonales and esophageal varices.