We have inserted epidural catheter for single or continuous injection of a drug for epidural analgesia. It is important to localize the tip of epidural catheter in appropriate site to acquire the most effective analgesia. In epidural block, we observed course and location of the tip of epidural catheter. Subject: 70 patients were divided into group I(non-injection of saline group during catheter insertion) and group II(injection group during catheter insertion). Group I included cervical(n=20), thoracic(n=10), and lumbar(n=20) epidural group. Group II, cervical(n=10), and lumbar(n=10) epidural group. Method: 19G FlexTip $Plus^{TM}$ Epidural Catheter ($Arrow^{(R)}$) was inserted 10cm cephaladly in epidural space with(group II) or without(group I) saline flushing. We observed course and location of the tip of epidural catheter by C-arm image intensifier during injection of contrast media ($Omnipaque^{(R)}$). Result: In group I, the number of tips of epidural catheters located within 2 cm from inserted site were: cervical 14/20(70%), thoracic 2/10(20%). lumbar 16/20(80%). In thoracic epidural blocks, tips of epidural catheters were more cephaladly located than with cervical and lumbar epidural blocks. With cervical epidural blocks, the number of tips of epidural catheters located within 2 cm from insertion site were less in group II than group I (20% vs. 70%). But no significant differences were noted between group I and group II with lumbar epidural block(90% vs. 80%). The number of tips of epidural catheters located around a predicted site were: cervical 2/20(10%), thoracic 4/10(40%), lumbar 0/20(0%) in group I, and cervical 2/10(20%), lumbar 1/10(10%) in group II. Conclusion: It was impossible to predict the exact location of tips of epidural catheters by measuring the inserted length without epidurogram. With many cases, tips of epidural catheters were located around the insertion site in lumbar epidural blocks, and in some cases around the predicted site in thoracic epidural blocks. The results suggests that epidural block should be done at a point near the required band of analgesia.