Abstract: Objective:To investigate the changes of serum paraoxonase-1(PON-1) activity,oxidized low-density lipoprotein(ox-LDL) level in acute ischemic stroke patients and analyze the clinical significance.Methods:Ninety-six acute ischemic stroke cases and 72 health subjects were selected.Serum PON-1 activity was measured using paroxon as substrate and ox-LDL level was detected by enzyme-linked immuno sorbent assay method.Total cholesterol,triglyceride,high-density lipoprotein-cholesterol and low-density lipoprotein-cholesterol levels were all measured in the two groups.The relationships of serum PON-1 activity,ox-LDL level and acute ischemic stroke were explored.Results:In ischemic stroke group,serum PON-1 activity and high-density lipoprotein-cholesterol level were significantly lower than those in control group( PPPPPPPPConclusions:In the patients with acute ischemic stroke,serum PON-1 activity was decreased and ox-LDL level was increased,the changes may be an important risk factor for ischemic stroke.It has an important meaning to forecast the risk of ischemic stroke.