Abstract: Objective To investigate influence of different doses of dexmedetomidine on hemodynamics of pregnancy-induced hypertension syndrome (PIH) patients with cesarean section.Methods A total of 325 PIH cases in our hospital were divided into control group and A,B,C,D groups,with 65 cases in each group.The control group received only basic anesthesia,A,B,C,D groups were given dexmedetomidine intravenous infusion of 0.1,0.2,0.3,0.4 μg/(kg · h),respectively.Systolic blood pressure (SBP),diastolic blood pressure (DBP),heart rate (HR) and other indicators before epidural administration (T0),skin incision (T1),fetal delivery (T2),at the end of surgery (T3) were recorded.Results SBP,DBP,HR of 4 time points in 5 groups had a significant difference (P ＜ 0.05).At T0,SBP,DBP and HR of 5 groups were significantly higher than that of T1,T2,T3 (P ＜ 0.05).At T1,SBP,DBP,HR were significantly higher than that of T2 and T3 (P ＜ 0.05),At T2,SBP,DBP,HR of 5 groups were significantly higher than T3 (P ＜ 0.05).At T0,SBP,DBP,HR among 5 groups showed no significant difference (P ＞ 0.05).At T1 ～ T3,DBP,HR SBP of the 5 groups had a significant difference (P ＜ 0.05),SBP DBP and HR in D group were significantly lower than that of A,B,C groups,and control group (P ＜ 0.05).SBP,DBP,HR in C group were significantly lower than B group,and the control group (P ＜ 0.05).SBP,DBP,HR in B group were significantly lower than A group and the control group (P ＜ 0.0 5);SBP,DBP,HR between A group and control group showed no significant difference (P ＞ 0.05).Conclusion The dose of 0.4 μg/(kg · h) for PIH patients with cesarean section has stable hemodynamics.With the increase of dexmedetomidine dose,the effect is more obvious.