The clinical parameters of 1 000 patients undergoing spinal aesthesia were recorded and analyzed.Hypotension fulfilling the predefined criteria occurred in 173 patients.The logistic regression analysis revealed that the regression coefficients of height,weight and amount of fluid infusion during anesthesia were negative while those of age,emergency operation,hypertension/hypotension,heart disease,American Society of Anesthesiologists score,use of sedative drugs and sensory blocking level of anesthesia positive.The area of receiver operating characteristic was 0.905.This study contributes to the identification of patients with high risks for hypotension after spinal induction.