To observe the anesthetic characteristics of two different speeds of injection using 0.5% plain bupivacaine during spinal anesthesia, 40 patients undergoing lower extremity surgery were allocated randomly into two groups. In one group, 3 ml of 0.596 plain bupivacaine was administered into the subarachnoid space using 25 gauge Quincke spinal needle to the patients with a lateral horizontal position at duration of 10 seconds. In the other group, the duration was 180 seconds. There were no statistically significant differences between two groups in maximal level and its onset time of sensory blockade, hemodynamic changes, onset time to grade 3 Bromage motor blockade. We concluded that the speed of injection does not affect the anesthetic characteristics of spinal anesthesia using 0.5% plain bupivacaine.