Abstract: Abstract: Objective To explore the changes of serum cholinesterase (ChE) in patients with sepsis and its clinical significance. Methods Estimate serum cholinesterase concentration and acute physiology chronic health evaluation (APACHE) Ⅱ scores in patients. Divide the patients into the sepsis group and the non-sepsis one. Divide the patients with sepsis into the death group and the survival one. Understand the changes of serum ChE levels between the groups and the impact on assessment and prognosis. Results (1) Serum ChE in patients with sepsis group was significantly lower than the control group (P <0.01). (2) In patients with sepsis, the serum ChE levels in the death group were significantly lower compared with the survival one (P <0.05). (3) The serum ChE levels in patients with sepsis were significantly negatively correlated with APACHE Ⅱ scores (r=-0.280, P <0.05), positively correlated with serum albumin and body mass index（r = 0.458 and 0.287，P＜0.05）. Conclusion Serum ChE levels can be used to determine the severity of illness and prognosis in patients with sepsis.

Key words: sepsis, serum-cholinesterase, APACHE Ⅱ score, prognosis