Objective To discuss the relationship of perioperative regional cerebral saturation of oxygenation (rSO2) and postoperative cognition function alteration of geriatric patients under intravenous anesthesia using creatine phosphate disodium salt,and to establish the clinical practical guides.Methods Sixty ASA Ⅰ-Ⅱ patients,aged＞60 y scheduled for selective abdominal surgeries or surgeries on lower limb were enrolled in this study.We used a completely randomized grouping design for this study and the 20 patients were divided into 3 groups:creatine phosphate disodium salt group 1 (C1),creatine phosphate disodium salt group 2 (C2),Control group (C).All patients were not premeditated with atropine 0.5 mg until entering the operation room.Anesthesia was induced with intravenous infusion of propofol,fentanyl and cisatracurium slowly,The anesthesia was maintained by intravenous propofol infusion in target controlled infusion target controlled infusion (TCI) (3 μg) and remifentanyl (0.2 μg·kg-1·min-1-0.4 μg·kg-1·min-1) infusion,intravenous bolus cisatracurium (0.07 mg/kg-0.10 mg/kg).After tracheal intubation,all patients were mechanically ventilated with expiration carbon dioxide pressure (PERCO2) at normal scale.The rSO2 was continuously monitored and recorded in operations.The mini-mental state examination (MMSE),trail-making test and grooved pegboard test were adopted to access cognitive function 24 h before surgery and 4,8,12,24 h after surgery.Results ① There were no significantly difference of general status among the three groups(P＞0.05).② The scales of MMSE,trail-making test and grooved pegboard test were not different 24 h before operations among three groups (P＞0.05).Compared with scales of MMSE before operation,4,8,12 h after operation in all patients were significantly lower (P＜0.05).Three groups of patients trail-making test and the grooved pegboard test time comparison experiment found:there were no difference between preoperative and postoperative testing time (P＞0.05),which time of patients in group C2 completed the task significantly shorter than group C1,the control group of patients needed more time to complete the task.Comparison of postoperative cognitive function changes after 4 h,cognitive function changes occurred in the control group of patients with 3 patients (15％),creatine phosphate (C2) of patients in group 1 patient (5％),creatine phosphate sodium (C1) patients,2 patients (10％).After 8 h,patients in the control group 2 patients (10％),creatine phosphate (C1) patients in group 1 patients (5％),phosphoric acid muscle sodium (C2) cognitive function in patients recovered.Postoperative 12 h,patients in the control group only one case (5％),creatine phosphate groups (group C1 and C2) cognitive function in patients recovered,after 24 h,cognitive function of all patients recovered,the delirium did not occur in all patients entered the study.(③ The scales of cognitive tests were higher in group C2 and group C1 than C (P＜0.01).The numbers of rSO2 in the three groups were identical (P＞0.05).Conclusions Creatine phosphate disodium salt can reduce the occurrence of postoperative cognitive dysfunction in geriatric patients combined the intravenous and inhalational anesthesia.The results may relate to its neural protection effects,unique natural energy supply and increasing central neural system tolerance of ischemia and hypoxia.