Abstract: Objective 　To measure the length of internal jugular vein puncture and catheterization and its transvascular  radius, so as to provide morphological basis  for central venous puncture and catheterization through the internal jugular vein in clinical practice.　Methods　Thirty-one adult gross cadavers were selected, and the entire course of the veins and their tributaries were dissected to determine the puncture entry point and the end point of the catheterization. The length from the left and right approach points to each tributary and to the end point, as well as the flattening diameter of the vessels were measured. The radius was calculated based on the flattening diameter.　Results　For the left approach, the average length to the subclavian vein was (20.47±9.08) mm; to the junction of the left and right brachiocephalic veins (91.17±14.12) mm; and to the end point (148.27±17.25) mm. For the right approach, the average length to the subclavian vein was (21.59±7.32) mm; to the junction of the left and right brachiocephalic veins (61.06±9.74) mm; and to the end point (123.22±12.68) mm. On the left side, the average radius of the internal jugular vein was (3.85±1.29) mm; subclavian vein (4.64±1.07) mm; and brachiocephalic vein (5.08±1.01) mm. On the right side, the average radius of the subclavian vein was (4.79±0.89) mm; internal jugular vein (5.03±1.65) mm; and brachiocephalic vein (5.23±0.91) mm. The average radius of the superior vena cava was (7.92±0.97) mm; and the azygos vein (4.16±1.21) mm.　Conclusions 　The right approach for internal jugular vein puncture and catheterization has greater advantages than the left side; a 20 cm catheter on the left side and a 15 cm catheter on the right side can basically meet clinical needs.

Key words: Central venous catheterization, 　Internal jugular vein, 　Anatomy