This studt was investigated to prove the effect of GMYM on the brain damage. The results were as follows; 1. GMYM showed significantly inhibitory effect on LDH release by NMDA. AMPA and Kinate. 2. GMYM showed significantly inhibitory effect on LDH release by BSO and Fe2+. 3. GMYM decreased coma duration time in a infatal dose of KCN and showed 30% of survival rate in a fatal dose. 4. GMYM showed improvement of forelimb and hindlimb test after MCA occulusion in neurological exemination. 5. GMYM decreased ischemic area and edema incited by the MCA blood flow block. These results indicate that GMYM can be used in the brain damage sujected to brain ischemia. Further study will be needed about the functional mechanism and etc.