The present study was designed to comparison of hemodynamic changes in unilateral spinal and epidural anesthesia in patients undergoing surgery below T10 sensory level. 120 patients aged between 18 to 70 years, with candidate of surgery below T10 sensory level that signed the written informed consent will be selected randomly divided into two group which receiving unilateral spinal and epidural anesthesia, separately. All patients who suffering from kidney, liver, cardiovascular diseases, coagulopathy, skin infection at injection site, sever hypervolemia, hypersensitivity to local anesthesia drug and sever hypotension will be excluded. The patients will be randomly allocated into one of two groups. In group one, patients receive unilateral spinal anesthesia. after subarachnoid injection in sitting position, patients are going to supine positions immediately and then Tilt to the surgical site (45 degrees). L2-L3 and L3-L4 space spinal Quinke G25 puncture spinal has done Approach midline. Then 3 cc Marcaine 0/5% is injected. In group two, patients receive epidural anesthesia. In Sitting position the epidural catheter is threaded the Tuohy G17 needle through L2-L3 or L3-L4 space. Loss of resistance techniques used to find the space. Epidural test dose of lidocaine ml 3 2% + μ / ml 5 epinephrine injected into the epidural space to ensure the integrity. After injected 15ml Marcaine 0/5%, the patient is given into supine position. Systolic and diastolic blood pressure, heart rate, saturated arterial oxygen, will be measured at the beginning and during the surgery and incidence of headache, backache, nasua and vomiting will be determined.