Abstract: To compare the neuroprotective and anti-dementia pharmacological effects of chiral oxiracetam, glutamate and calcium ions were used to establish neuronal injury models in vitro, and the protective effects of chiral oxiracetam on primary neurons were assayed by MTT. Permanent bilateral common carotid artery occlusion (2-VO)-induced rats were randomly divided into sham group, model group, galantamine 3 mg‧kg^-1 group, oxiracetam groups (30, 100 and 200 mg‧kg^-1), S-oxiracetam groups (30, 100 and 200 mg‧kg^-1) and R-oxiracetam 200 mg‧kg^-1 group. The animal experiments in the present study were performed in accordance with the Ethical Guidelines of the Laboratory Animal Welfare Ethical Committee of Peking Union Medical College. Morris water maze and step-down test were applied to evaluate the cognitive dysfunction induced by cerebral hypoperfusion in rats. Oxiracetam, S-oxiracetam and R-oxiracetam exerted protective effects on primary neuronal damage caused by various stimuli, and oxiracetam and S-oxiracetam showed better neuro-protective effects. Morris water maze and step-down results showed that oxiracetam, S-oxiracetam and R-oxiracetam improved the cognition of 2-VO rats. In summary, S-oxiracetam exerted a better neuro-protective effect than oxiracetam and R-oxiracetam.