The internal jugular and subclavian veins are considered as satisfactory intravenous routes for rapid blood and fluid replacement. To determine whether these venous pressures can be used as reliable guides for central venous pressure monitoring, simultaneous measurements of the Rt. internal jugular venous pressure and central venous pressure (CVP), or Rt. subclavian venous pressure and CVP using long 14 gauge catheter were made in 20 patients undergoing cardiac anesthesia. The results were as follows: l. Each mean value of the Rt. internal jugular venous pressure and CVP was 10.64±5.43 cm H2O and 10.05±5.55cm H2O (Mean±SD) respectively in first 10 patients. Pressure difference was 0.59±0.39cm H2O (p<0.005). 2. Each mean value of the Rt. subclavian venous pressure and VP was 7.77±3.37 cm H 0 and 7.05±3.49cm H2O (Mean±SD) respectively in second 10 patients. Pressure difference was 0.73±0.59cm H2O (p<0.005). 3. There were significant correlations between Rt. internal jugular venous pressure and CVP (r=0. 99, p<0.005) as well as between Rt. subclavian venous pressure and CVP (r=0.98, p<0.005). The results suggest that Rt. internal jugular or subclavian vein catheterized with short intravenous catheter during Anesthesia can be used as effective and reliable guides for CVP monitoring because pressure differences with CVP were small and consistant.