目的　探讨慢性低灌注状态下脑部能量代谢改变对认知功能的影响和可能的影响机制。方法　雄性SD大鼠 6 0只 ,随机分为 3组 :缺血 1月组 2 5只 ,缺血 3月组 2 5只 ,对照组 10只。缺血组大鼠行双侧颈总动脉结扎 ,在试验的不同阶段对各组大鼠行水迷宫试验和跳台试验 ,并按期取脑行ATP酶、乳酸脱氢酶 (LDH)组织化学染色。结果　各缺血组大鼠在行为学功能上较对照组有显著减退 ,缺血 3月组更为明显。各缺血组大鼠海马CA1区ATP酶活性显著降低、乳酸脱氢酶活性升高。结论　经双侧颈总动脉永久结扎后形成的脑部慢性低灌注状态并导致的神经元能量代谢水平降低和功能紊乱可能引起认知功能减退。 Objective To investigate the effect of changes in brain energy metabolism on cognitive function and its possible mechanism under chronic hypoperfusion. Methods Sixty male Sprague-Dawley rats were randomly divided into 3 groups: 25 in January of ischemia, 25 in March of ischemia, and 10 of control. Rats in ischemia group were subjected to bilateral common carotid artery ligation. Rats in each group were subjected to water maze test and step-down test at different stages of the experiment. Tissue chemistry staining of ATPase and lactate dehydrogenase (LDH) was performed in each group. Results Compared with the control group, the rats in each ischemic group had a significant decrease in their behavioral function and the ischemic group was more obvious in the March group. The ATPase activity of hippocampal CA1 region was significantly decreased and the activity of lactate dehydrogenase was increased in each ischemia group. Conclusions The chronic cerebral hypoperfusion caused by permanent ligation of common carotid arteries leads to the decrease of neuronal energy metabolism and dysfunction, which may lead to cognitive decline.