The changes of onset and duration of caudal epidural anesthesia had been compared in 54 patients schedulled for perianal surgery at kyungpook National University HospitoL The patients were divided into 3 groups of 18: lidocaine group received 2% lidocaine 20 ml, mixture group received 2% lidocaine 10 ml and 0.5% bupivacaine 10 ml and bupivcaaine group received 0.5% bupivacaine 20 ml. The onsets were as follows. The onsets wiere 3.11±0.63 in lidocaine group, 4.83±4.17 in mixture group and 8.13±3.49 min in bupivacaine group. The onset of bupivacaine group was slower than lidocaine group(p<0.01) and late compared with mixture group(p<0.5). The duration of caudal anesthesia were 192.00±62.49 in lidocaine group, 326.72±145.28 in mixture group and 419.22±125.37min in bupivacaine group. Significant differences were observed between mixture-lidocaine group(p<0.01), bupivacaine-lidocaine group(p<0.01) and bupivacaine-mixture group(p<0.05). Urinary catheteiized patients were 8 in longest duration group of bupivacaine. It is suggested from the above'results that the mixture of lidocaine and bupivacaine during caudal epidural anesthesia can produce rapid onset and long duration.