Vasuclar access is commonly established by puncture of intemal jugular vein because of various medical causes; however,puncture of intemal jugular veins may lead to occurrence of complications.The anatomic relationship between internal jugular vein and common carotid artery has some variations and is affected by age,puncture sizes,and head position.Detailed understanding of internal jugular vein,anatomic relationship between internal jugular vein and common carotid artery,and the related affecting factors are the basis to improve the success rate of puncture and to reduce occurrence of complications.