Ｏｂｊｅｃｔｉｖｅ　To examine the effect of ultrasound-guided stellate ganglion block (SGB) on the tourniquet reaction of the lower limbs.　Methods　A total of sixty patients undergoing unilateral knee replacement surgery under general anesthesia were divided into 2 groups (n=30): control group and group SGB. The age of patients was 18-75 years old with ASA gradeⅠ,Ⅱ. Before general anesthesia, 1% lidocaine (10 ml) was injected into the right deltoid muscle in control group, but in the right cervical stellate ganglion in group SGB. HR, SBP, BIS and drug doses were recorded at various time points: before induction of anesthesia (T0), before intubation (T1), 1 min after intubation (T2), before tourninquet inflated (T3), tourniquet inflatable 30 min (T4), tourniquet inflation 1 h (T5), tourniquet deflation(T6), tourniquet deflation 3 min (T7) and tourniquet deflation 30 min (T8) after discharge.　Results　Compared with control group, group SGB showed significantly lower SBP at T2, T5, T6 and T7 (P<0.05), while significantly smaller HR changes at T2 and T7 (P<0.05). There was no significant difference at T0, T3 and T8 between the two groups (P>0.05). There was no significant difference in the BIS, the doses of propofol, remifentanil, ephedrine and phenylephrine between the two groups, while the dose of urapidil in group SGB was significantly less than control group.　Conclusions　SGB can reduce the cardiovascular response to the tourniquet and maintain stable perioperative circulation.