Abstract: The present invention provides therapeutically active oxazolidine derivatives and compositions as NMDA antagonists, which are useful in preventing and treating central nervous system disorders by inhibiting over-activation of NMDA receptors. In one aspect, the present invention provides methods of treating and/or preventing neurodegenerative diseases and neuropathological disorders, methods of providing neuroprotection under stress conditions such as a stroke, and methods of enhancing the brain's cognitive functions in mammals and humans. For example, the compounds can prevent glutamate-induced neuro-toxicity by inhibiting the activities of the NMDA receptor in the presence of toxic doses of NMDA. In addition, the compounds can potentiate the calcium current in the presence of low dose of NMDA.