The purpose of this study was to observe the effect of spinal anesthesia on serum glucose which is still controversial and to observe the changes of serum glucose according to the blocked level and intrathecal morphine and epinephrine mixed with local anesthetic(tetracaine). 67 patients(age; 16-83, ASA. ps. 1-3) for lower abdominal or lower extremity operation, had no disease affecting serum glucose level and were not contraindicated for spinal anesthesia, were selected randomly and divided them into each 3 group depending on the sensory block level and with or without intrathecal morphine and epinephrine mixed with local anesthetic (tetracaine) as fo11ows; Ggroup l (N =8); high spinal anesthesia(above T4) Group 2(N=23); middle spinal anesthesia(T5~T9) Group 3(N=26); low spinal anesthesia(below T10) Group A(N=18): tetracaine only Group B(N=17); tetracaine+epinephrine(0.2 mg) Group C(N = 32); tetracaine+ epinephrine(0.2 mg)+ morphine(0.2 mg) All patients except emergency cases were premedicated with nalbuphine(5 mg) and droperidol(2.5mg) or hydroxyzine(1 mg/kg) and were kept NPO 6-12hr. Hartman's solution were used for the maintenance fluid. Serum glucose were measured before operation, just immediate before and after spinal anesthesia and at 30 min. after starting operation with Glucometer-2(Miles inc, Indiana, USA). The results were as follows; 1) The values of serum glucose after spinal anesthesia were not changed significantly compared with those of the immediate before anesthesia(P> 0.05). 2) The values of serum glucose according to sensory block level were not changed significanly compared with each group(P>0.05). 3) The values of serum glucose when using mixed epinephrine and morphine with tetracaine intrathecally were not changed significantly compared with using tetracaine only(P>0.05). These results suggested that spinal anesthesia itself did not affect serum glucose level, and neither the sensory block level nor iatrathecal epinephrine and morphine affect serum glucose level. Increased serum glucose caused by surgical stress might be attenuated by spinal anesthesis when lower extremity and lower abdominal operation.