The purpose of this study was to evaluate and compare the effectiveness of ilioinguinal-hypogastric nerve blocks(IHNB) and caudal block in producing post-orchiopexy and post-heniorrhaphy analgesia in children. Forty consenting healthy children, ages 3~10yr, were randomly assigned to receive caudal bupitvacaine (0.125%, 0.5ml/kg), or IHNB bupivacaine (0.25%, 0.3 ml/kg). Blocks were performed following the induction of general anesthesia, be fore the operation. Pre-anesthetic medication in form of atropine 0.01 mg/kg, droperidol 0.05 mg/kg were given intramuscularly one hour before induction to 40 children. Children were induced with thiopental sodium 5 mg/kg and succinylcholine 1 mg/kg intravenously. Anesthesia was maintained with oxygen-nitrous oxide ($FiO_2$ 0.3) and ethrane. When the patients stabilized after induction. IHNB was done in the supine position and caudal block was done in the lateral position. The local anaesthetic was injected after negative aspiration. Postoperative pain was assessed with face pain rating scale (RPRS) at rest on discharge of recovery room, and 5 hours after discharge of recovery room, and the "red and white" visual analogue scale (VAS) at rest and mobilization from supine to sitting position on discharge of recovery room, and 5 hours after discharge of recovery room. Post-operative recovery was quiet and comfortable, without side effect. Relief of ain was complete in both IHNB group and caudal group. Surgeons, parents and recovery room personnel were satisfied. There were no surgical or anesthetic complications. In our study, the postpoerative pain scores were similar in both IHNB group and caudal group. IN conclusion, we found that both IHNB and caudal blocks before the start of surgery for orchiopexy & herniorrhaphy are safe and effective in controlling the postoperative pain of children.