Objective To compare the effects of preload with intravenous infusion of 6％ hydroxyethyl starch combined with phenylephrine or dopamine to prevent the hypotension after combined epiduralspinal anesthesia in parturient undergoing caesarean section.Methods Eighty patients with ASA class Ⅰ or Ⅱ[,were randomly divided into Dopamine group and Phenylephrine group,40 cases in each group.The 6％hydroxyethyl starch 500 ml was infused at the tate of 20 ml/(kg · h) after the intravenous catheterization was established and after the finishing of the infusion of 250 ml,the dopamine 5 mg (Dopamine group) or 200 ug phenylephrine (Phenylephrine group) were added respectively in residual liquid.After the bupivacaine was injected into the subarachnoid space,the intravenous infusion was continued at the same rate until the fetus was taken out and the blood pressure and heart rate were measured at intervals of 1 min.The blood sample of fetal cord was taken to measure ther troponin Ⅰ concentration.Results The incidence of hypotension after combined epidural-spinal anesthesia anesthesia in dopamine group (2/40) and in phenylephrine group (3/40) was with no statistical difference (P ＞ 0.05) ;The incidence of bradycardia in dopamine group (0/40) was significantly lower than that in phenylephrine group (6/40)) (P ＜0.05) ; The incidence of tachycardia in dopamine group (8/40) was significantly higher than that in phenylephrine group (1/40) (P ＜0.05) ; The troponin Ⅰ concentration of fetal cord blood in dopamine group [(0.21 ±0.07) ng/ml] and in phenylephrine group [(0.18 ±0.09)ng/ml]was with no statistical difference (P ＞0.05).Conclusion Preload with intravenous infusion of 6％ hydroxyethyl starch combined with phenylephrine or dopamine can effectively prevent the hypotension after combined epidural-spinal anesthesia in parturient undergoing caesarean section with no significant effect on the fetus and both can be chosen in terms of the heart rate of parturient before anesthesia.