Background: Present clinical study was conducted to study the effects of intravenous Magnesiun Sulphate on spinal anesthesia with Bupivacaine and Buprenorphine, Methods: After thorough pre anaesthetic evaluation , Pre operative vitals para meters in the form of baseline pulse, blood pressure pulse were recorded. A good venous access was taken. Patient connected to ecg, pulse oximetry, non invasive blood pressure monitoring. Patients randomly allocated into two groups: Group M-50 received 50mg/kg intravenous MgSO4 in 500ml Ringer lactate over 20 mins. Group C-50 received intravenous 500ml Ringerlactate over 20 mins. Both the groups received intrathecal 15mg of Inj.Bupivacaine (0.5%) and 30 mcg of Inj. Buprenorphine