In our hospital we studied the effects of spinal anesthesia with 0.5% isobarie bupivacaine and hyperbaric T-caine in 60 patients undergoing operation of lower abdomen or lower limbs. The following results were obtained. 1) Maximum level of sensory loss were similar in both groups, the time taken to it was significantly faster in the T-caine group but the duration was significantly longer in the bupivacaine group. 2) Onset time of motor blockade was significantly faster in the T-caine group but the duration was significantly longer in the bupivacaine. 3) The fall in blood pressure appeared faster in the T-caine group but no significant value of difference between the two groups. No significant changes were noted in the pulse rates. 4) Post spinal headache developed in 5 patients out of 60 patients (8.3%). With the results, we can assume that 0.5% isobaric bupivacaine is a good local anesthetic agent for spinal anesthesia in operations of the lower abdomen and lower limbs.