Abstract： Objective To research the effect of regulating systemic inflammatory response by using ulinastatin in elderly patients after sevoflurane inhalation of postoperation cognitive function. Methods 60 patients under went elective abdominal surgery, were randomly double-blinded divided into 2 groups. Every group had 30 patients.Group A accepted continuously intravenousiy infusion ulinastatin 2000 units · kg-1 · h-1 , while group B got equivalent continuously intravenous infusion 0.9% sodium chloride injection. The time point of opening eye, extubation, response and the mini-mental state examination(MMSE) score on different time points were observed. Meanwhile, the changes of concentration of hs-CRP, IL-6,IL-10 were measured. Results Compared with two groups,group A has shorter time on response(F =4.399,P = 0.040). Two both groups had decrease of MMSE score 1 hour after surgery compared with preoperation(t =7. 732,11. 916, both P ＜ 0.01), and the score were less than the preoperative value of more than 2 points which showed cognitive decline in patients. But group A's rate of decline in MMSE score was lower than group B(F = 7. 582 ,P =0.012). Both groups had the MMSE score decline 6h after surgery (t = 4. 606,8. 615, both P ＜ 0.05). Group A's score was less than the preoperative value for less than 2 points, group B's score was lower than the preoperative value for more than 2 points, but the difference between the two groups was not significant (P ＞0. 05). Both groups had higher concentrations of hs-CRP、IL-6 、IL-10 at postoperative 1 d ,3d ,7d (all P ＜ 0.01), peaked at postoperative 1 d, and hadn't come back to the preoperative level 7d*after surgery. In group A, the concentrations of hs-CRP, IL-6 increased (postoperative 1 d,3d), but the rate was lower than the group B (F = 14. 885, P = 0.000;F = 4. 405, P = 0. 040; F = 18. 204, P = 0.000; F = 8. 074, P = 0. 006); while the increased rate of concentration of IL-10 was higher than the group B(F=5.197,P=0.026;F= 12.236,P =0.000). Conclusion Ulinastatin could promote the elderly after sevoflurane inhalation rapid recovery of cognitive function, which may be related to the regulation of systemic inflammatory response.