In our department we selected 52 patients in ASA Class I, aged from 20 to 60 years old undergoing operation of lower limbs and lower abdomen, lasting 1 to 2 hours of duration. They were divided into 2 groups, group A (30 patients) using 0.5% hyperbaric Tcaine 13 mg (2.6 ml), group B (22 patiens) using 0.25% hyperbaric bupivacaine 10 mg (4 ml), which were injected into intrathecal space. Sensory loss level was significantly higher in group A than in group B. The time taken for the block to reach maximum level was significantly faster in group B. Analgesic duration was significantly shorter in group B. In group B, onset of motor blockade was significantly slower and also, the total duration was significantly shorter. In group A, significant decrease of diastolic and systolic blood presssure were noted. Hyperbaric 0.25% bupivacaine can be used for short timed operation of lower limbs and lower abdomen without changes of cardiovascular system.