【Abstract】 Objective To investigate during the general anesthesia, the effect of different sedation depth of anesthesia the BIS settings for both 45 and 55 to the perioperative inflammatory reaction. Methods Thirty-two ASA Ⅰ-Ⅱ patients whose age were choosed 18 to 75yr，BMI 22~27kg/m2 undergoing gastrointestinal surgery were randomly divided into two groups: group BIS45、 group BIS55 (n = 16 each). Through closed-loop target controlled infusion technology to maintain different depth of sedation anesthesia in group BIS45 the BIS = 45, group B the BIS = 55. Venous blood samples were collected before surgery (T1), the start of the surgery two hours(T2),after the start of the surgery 24 and 72 hours postoperatively (T3, T4) for determination of plasma concentrations of interleukin-6, IL-10. Results Between the two groups, the T2 time point in group BIS45 than group BIS55, plasma cytokine interleukin-6(IL-6) and interleukin-10(IL-10) values was significantly increased (P = 0.048, P = 0.005). Plasma cytokine IL-6 within the two groups, group BIS45 at T2 than at T1 was significantly increased (P = 0.026) , plasma IL-10 within the two groups, group BIS45 at T2 than at T1 was significantly increased (P = 0.007). Conclusion The sedation anesthesia depth of BIS values 55 for surgery keep stable of inflammatory cytokines ,while the depth of BIS values 45 caused significantly increased of the preoperative cytokines. Therefore, the sedation anesthesia in BIS values 55 compared to BIS 45 inflammatory reaction is lighter.