Objective　To observe the change of hemodynamics， plasma concentration of nitric oxide （NO） and tumor necrosis factor-alpha （TNF-α） during combined spinal-epidural anesthesia （CSE） for cesarean section in preeclamptic patients.　Methods　Forty-nine pregnant women， 25 healthy women at（36 weeks+3）-40 weeks′ gestation and 24 women with severe preeclampsia， were scheduled for elective cesarean section（n=24）. All patients were underwent CSEA with 0.75% hyperbaric bupivacaine at dose range of 10 mg-12 mg， and the sensory block height was controlled at T6~8. Changes of hemodynamic parameters， plasma concentration of NO and TNF-α of the puerperas，body weight and Apgar score of the neonates were observed during anesthesia.　Results　There was significant decrease in the lowest systolic pressure， diastolic pressure and mean arterial pressure of all patients after spinal anesthesia compared with their basic level （P<0.05）， and the decreasing extent was similar between the two groups. There was no difference in incidence of hypotension， the total dose of ephedrine， neonates' body weight and Apgar score between the two groups. The concentration of plasma NO in preeclampsia group ［（732±213） mmol/L］ was significantly lower than that in healthy group ［（3 473±231） mmol/L，P<0.01］， and the level of plasma TNF-α in preeclampsia group ［（2 103±371） ng/L］ was significantly higher than that in healthy group ［（1 321±325） ng/L，P<0.01］.　Conclusions　Combined spinal-epidural anesthesia is feasible for cesarean section. Increasing of TNF-α release and decreasing of NO synthesis may be the reduplicative factors which lead to the hypertension of preeclamptic patients