We experienced two cases whose epidural catheter migrated into subarachnoid space. Case 1 was a 74 years old woman who received spinal fusion of T9-S1. A single shot epidural block was performed before surgery at L3/4. At the end of surgery, an epidural catheter was inserted by direct vision at L1/2. After single injection, ropivacaine 0.25％ was infused at 8 ml/h. Both legs paralyzed 17 hours later. The catheter was removed and paralysis was resolved. Case 2 was 81 years old woman who received spinal fusion of T5-L1. An epidural block was performed at T11/12 before surgery. At the end of surgery, an epidural catheter was inserted at T10/11 by direct vision. After single injection, levobupivacaine 0.1％ 6 ml/h and fentanyl 25 µg/h was infused. Bilateral leg motor weakness happened 29 hours later. The catheter was removed and weakness improved. An epidural catheter inserted during surgery by direct vision might migrate into subarachnoid space.